Changelog

v0.61.2 (unreleased)

Contributors to this version: Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal).

Breaking changes

• Fix maximum_consecutive_* indicators to harmonize them with their docstring, add op argument to control comparison and fix some non-existing standard names. (GH/2368, PR/2370).

Internal changes

• zizmor added to pre-commit hooks. GitHub workflow permissions have been adapted for better security settings by default. (PR/2367):

  • Adjusted the token creation permissions to prevent creating tokens with unnecessary access privileges.

  • ReadTheDocs OS version updated to ubuntu-26.04.

  • workflow-warning.yml now simply uses GitHub API calls.

v0.61.1 (2026-05-25)

Contributors to this version: Pascal Bourgault (@aulemahal).

Bug fixes

• Fix conversion error with xc.units.rate2amount and xc.units.amount2rate when sampling_rate_from_coord=True or sampling frequency is monthly or coarser and time coordinate is cftime-based. Previous results were 1000x too small. (PR/2357).

• For the Canadian Forest Fire Weather Index System, add non-null default starting values for dc0 and dmc0 if the dry start mechanism is activated. (GH/2371, PR/2372).

Internal changes

• Fixed documentation generation with Sphinx v9.0 by activating the legacy autodoc system. (PR/2358).

v0.61.0 (2026-05-07)

Contributors to this version: Pascal Bourgault (@aulemahal), Trevor James Smith (@Zeitsperre), Hui-Min Wang (@Hem-W), Éric Dupuis (@coxipi).

Announcements

The next major release of xclim will be v1.0. This new version will have some significant breaking changes such as:

• Migration of xclim.indices module into the new xclim.compute module for more efficient indicator composition.

• xclim.indicators.generic refactoring to remove lots of redundant code in favour of more standardized and easier-to-use primitive functions.

Users should expect that existing scripts may need to be updated in order to continue operating as usual. The xclim developers may release some patch versions to address small issues before v1.0. We suggest temporarily pinning your dependencies (xclim <1.0) if your workflows require significant effort to adapt to changes, particularly if they depend on direct calls within xclim.indices. A migration guide will be made available within the official documentation.

For more information on what will comprise the next major release and some future goals of xclim v1.0, consult the meta-issue here: GH/2352.

New indicators and features

• xclim.indices.generic.doymin and xclim.indices.generic.doymax will now return nan if all values along the time axis are the same. They now also support all-nan arrays (PR/2314).

  • This changes the behaviour for indicators land.snw_max_doy, land.snd_max_doy, land.doy_qmin and land.doy_qmax.

• Added two zero_inflated arguments to xclim.indices.stats.standardized_index and xclim.indices.standardized_precipitation_index to control how zero-precipitation probabilities are handled. (GH/2279, PR/2280).

• xclim.indices.stats.parametric_pdf allows to compute PDF distributions with given input parameters and values (PR/2323).

• xclim.indices.standardized_precipitation_index and xclim.indices.standardized_precipitation_evapotranspiration_index now can accept genextreme and lognorm as inputs for dist. (GH/2326, PR/2327).

Internal changes

• Documentation adjustments. (PR/2325):

  • Updated the intersphinx directives to point at new xsdba sphinx documentation targets.

  • Updated the ReadTheDocs configuration to build docs with an older Python version and a newer conda version.

  • Updated the pre-commit hooks (check-jsonschema) in order to accept the latest supported conda version in ReadTheDocs config.

  • Set docs/conf.py to ignore sphinx_autodoc_typehints.guarded_import errors raised by xarray type guarding.

• Set SocketBlockedError to be a subset of the Exception class when pytest-socket is not installed. (PR/2324).

• Carbon and energy reporting via green-coding-solutions/eco-ci-energy-estimation has been configured to better aggregate results for the xclim main branch as well as for all Pull Requests. (PR/2090).

• xclim now has a set of guidance documents on the kinds of AI-assisted contributions that are considered acceptable and how they must be disclosed (AGENTS.md, AI_POLICY.md, new section in CONTRIBUTING.rst). (GH/2321, PR/2346).

• The README.rst file now shows the Ouranos logo. In rendered documentation, the logo style is dynamic to the light/dark theming. (PR/2349).

Breaking changes

• The choice of method “APP” was removed when using a genextreme distribution in standardized indices (xclim.indices.standardized_index and related functions). (GH/2326, PR/2327).

Bug fixes

• dist in xclim.indices.standardized_index can now be a scipy.stats.rv_continuous as previously announced. (GH/2326, PR/2327).

• sphinx-autodoc-typehints has been pinned due to recent build failures on ReadTheDocs. (PR/2090).

v0.60.0 (2026-01-23)

Contributors to this version: Éric Dupuis (@coxipi), Trevor James Smith (@Zeitsperre), Juliette Lavoie (@juliettelavoie), Ève Larose (@e-larose), Faisal Mahmood (@faimahsho), David Huard (@huard), Pascal Bourgault (@aulemahal).

Breaking changes

• lmoments3 is now listed as a dependency to the extras installation recipe. This dependency is not installed by default with xclim and must be explicitly requested with $ pip install "xclim[extras]", if desired. (PR/2269).

• numpy-related RuntimeWarnings for invalid operations are noisier when running calculations via the xclim.indices and muted by default for xclim.indicators. This change is made to ensure that users who perform indice calculations can be made more aware of potential inconsistencies in their source datasets. (GH/2277, PR/2276).

• xclim.core.calendar.time_bnds now follows the CF conventions in that the “end” time is the same as the “start” of the next period (and not the timestep just before). (PR/2310).

• The keep_attrs option was removed from xclim.set_options. The recent change in philosophy from xarray` has rendered xclim attribute preservation logic irrelevant. The xarray option now controls all attribute management. (GH/2308, PR/2311).

New indicators and features

• xclim now officially supports Python 3.14. (GH/2259, PR/2305).

• New missing algorithm: xclim.core.missing.some_but_not_all. (PR/2290).

• New hydrological indices added to xclim.indices._hydrology.py. (GH/1624, PR/2227).

Bug fixes

• One of the conditions in xclim.atmos.cooling_degree_days_approximation had an erroneous computation and has been fixed: (tasmax - tasmin)/4 is replaced by (tasmax - thresh)/4. (GH/2272, PR/2273).

• Fix some issues with pandas v3.0 in partitioning functions of xclim.ensembles and in xclim.indices.generic.aggregate_between_dates. (PR/2310).

Internal changes

• Replaced the tox.ini file with a tox.toml file and simplified the conditionals for environment selection. (PR/2269).

• Removed python-coveralls from the tox-only dependencies (abandoned software / not supported in Python 3.13+) and added the coverallsapp/github-action step to PyPI/tox-based builds on CI. (PR/2269).

• The testing suite has been updated to support pytest >=9.0 (PR/2276):

  • The configuration in tox.toml now uses the new TOML conventions.

  • –strict-config and –strict-markers have been replaced with the new –strict mode. For more information, refer to the pytest documentation.

• Added a GitHub Workflow for automatically approving Dependabot Pull Requests that are either patch or minor updates. Dependabot is now configured to run on a monthly basis (previously weekly). (PR/2292).

• Dependabot auto-approved pull requests are now also set to auto-merge. (PR/2300).

• Build-cancelling based on concurrency rules for the main.yml GitHub Workflow are now also divided according to the github.event_name (pull_request, pull_request_review). (PR/2301).

• Added the rst-check hook to .pre-commit-config.yaml for ensuring that ReStructuredText roles, directives, and spacing are consistent with repository configurations. (GH/2133, PR/2306).

• Replaced the formattext-pre-commit hook with mirrors-bibtex-tidy in order to enforce style and consistency on BibTeX files. (PR/2306).

• Removed many obsolete noqa comments from throughout the code base. (PR/2307).

• matplotlib is no longer loaded during the import process of xclim nor during the pytest` setup phase if it is installed in the active environment. (PR/2307).

v0.59.1 (2025-10-31)

Contributors to this version: Trevor James Smith (@Zeitsperre).

Internal changes

• Updated the example.ipynb notebook to use a newer dataset based on CMIP6 for the workflow showcase; The previous dataset based on CMIP5 has since been retired, and the broken URL was causing documentation build failures. (PR/2261).

v0.59.0 (2025-10-30)

Contributors to this version: Pascal Bourgault (@aulemahal), Trevor James Smith (@Zeitsperre), Sascha Hofmann (@saschahofmann).

New indicators and features

• xclim.ensembles.robustness_fractions now accepts instances of xclim.core.missing classes as a new invalid argument to control how data points are flagged as invalid. (PR/2245).

• xclim.indices.stats.fit now returns NaNs when running with method PWD and a lmoments distribution. Before it failed with an L-Moments invalid error. (GH/2235, PR/2239).

Breaking changes

• The relative humidity computations from specific humidity, pressure and temperature (vapor_pressure and relative_humidity) were modified to use the fraction of vapour pressure to saturation vapour pressure instead of an incomplete equation with the mixing ratios. Changes are small, but sometimes not negligible. (PR/2254).

• black and blackdoc are no longer required for development. ruff is now exclusively used for code and code-block formatting. (PR/2249).

• Python HDF5 libraries now have lower pins to ensure modern versions are preferably installed (h5netcdf >=1.5.0 and h5py >=3.12.1) (PR/2253).

Bug fixes

• Fix dimensions of “prsn” in the variable dictionary. (PR/2242).

• History is not written to the DataArray if the as_dataset option is activated. (GH/2240, PR/2251).

• xclim.core.formatting.update_history now places the updated history at the top of the new attribute, not at the bottom. (PR/2251).

• $ xclim info CLI utility now provides information for module-loaded indicators (cf, anuclim, icclim). (GH/2219, PR/2255).

• A few functions have been adapted to the new xarray default (True) for option keep_attrs. (GH/2250, PR/2257).

Internal changes

• Fixed an issue with a test that can fail when running with older versions of numpy. (PR/2253).

• Updated flit to v3.11.0 and adopted PEP 639 for specifying licensing metadata. (PR/2260).

v0.58.1 (2025-08-28)

Contributors to this version: Pascal Bourgault (@aulemahal).

Internal changes

• Unpin scipy to allow version 1.16 and higher. (PR/2236).

v0.58.0 (2025-08-27)

Contributors to this version: Sebastian Lehner (@seblehner), Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal), Éric Dupuis (@coxipi), Baptiste Hamon (@baptistehamon).

New indicators and features

• New indicator xclim.atmos.antecedent_precipitation_index computes the antecedent_precipitation_index (weighted summation of daily precipitation amounts for a given window). (GH/2166, PR/2184).

• Argument indexer added to indicators max_n_day_precipitation_amount, max_pr_intensity, and blowing_snow. (GH/2187, PR/2190).

• Argument window added to indicator rain_on_frozen_ground_days. (PR/2190).

• New helper xclim.indices.generic.season_length_from_boundaries takes season_start and season_end as input and gives season_length. This is used when starts and ends are computed with different resampling frequencies: days_since are used to compute temporal lengths in this case. (PR/2189).

• Allow invalid_values as argument for relative_humidity_from_dewpoint. (GH/2202, PR/2203).

• New thermodynamic conversion indicators (GH/2165, PR/2206):

  • xclim.convert.vapor_pressure to compute the partial pressure of water vapor from specific humidity and total pressure.

  • xclim.convert.dewpoint_from_specific_humidity to compute the dewpoint temperature from specific humidity and total pressure.

• All functions using saturation vapour pressure can now compute it with a smooth transition between saturation over ice and saturation over water. The transition is controlled by the interp_power , ice_thresh and water_thresh parameters. (GH/2165, PR/2206).

  • New methods "buck81" and "aerk96" and new method "ECMWF" which is "buck81" on water and "aerk96" on ice.

  • Saturation vapor pressure calculations were reorganized. xclim.indices.converters.ESAT_FORMULAS_COEFFICIENTS now stores the August-Roche-Magnus formula’s coefficients.

• New indicator xclim.atmos.hot_days as counterpart to xclim.atmos.frost_days. (GH/2194, PR/2213).

• New helper indices for computing the day-length coefficient for viticulture growing seasons based on several approaches:

  • xclim.indices.helpers.gladstones_day_length_coefficient: Based on the Gladstones (1992, 2011) method.

  • xclim.indices.helpers.huglin_day_length_coefficient: Based on the Huglin (1978, 1998) method.

  • xclim.indices.helpers.jones_day_length_coefficient: Based on the approach outlined in Hall and Jones (2010).

• The xclim.indices.helpers.day_length function now accepts an infill_polar_days argument to control whether polar days or polar nights are filled with NaNs (infill_polar_days=False; default behaviour) or with a day length of 0 or 24 hours, depending on the date (infill_polar_days=True). (GH/2201, PR/2207).

• The indices for uas_vas_to_sfcwind, sfcwind_to_uas_vas, rle_1d, and cffwis_indices now provide their outputs via the NamedTuple format. This provides a method for accessing indice outputs using variable names in addition to positional indexing. (PR/2224).

• The new xclim.indicators.convert module is now available to provide a distinct API for conversion-focused indicators. This module is intended to regroup all conversion-based indicators that were previously scattered across different indicato realms. This module is also accessible via xclim.convert. (GH/1289, PR/2224).

• New methods dai_annual and dai_seasonal for xclim.convert.snowfall_approximation and xclim.convert.rain_approximation, taken from Dai [2008]. Indicator also take new argument landmask to switch between the land and ocean formulations. (PR/2208, GH/1752).

Breaking changes

• The "jones" method for calculating ‘k’ in xclim.indices.huglin_index and xclim.indices.biologically_effective_degree_days now require daily data computed at annual frequencies (freq="YS"|"YS-JAN"|"YS-JUL"). The previous behaviour for non-annual frequencies was undefined. (GH/2201, PR/2207).

  • The "jones" method now sets a floor value for "k" where it is not allowed to be less than 1.0. This is to avoid values below 1.0 for "k" which were previously allowed in xclim but not supported by the source literature.

  • Incomplete growing seasons (where the values of "k" for all latitudes during the growing season are all below 1.0) will now raise ValueError. This is to ensure that the expected output is consistent with the literature.

• The "gladstones" method for calculating ‘k’ in xclim.indices.biologically_effective_degree_days now uses a dedicated function based on a dynamic day_length compared to a reference latitude (40 degrees). The previous implementation of the "gladstones" method was based off an approximation found in Hall and Jones (2010). (GH/2201, PR/2207).

  • The "gladstones" approximation is now available as a separate helper function: xclim.indices.helpers.jones_day_length_coefficient with method="gladstones".

• The "icclim" method for calculating ‘k’ in xclim.indices.huglin_index has been renamed the "huglin" method. The "icclim" method was identical to the implementation proposed in Huglin (1978). (GH/2201, PR/2207).

• The xclim.indices._conversion submodule has been refactored into the new xclim.indices.converters module. Directly importing functions from the older location will still work but will emit a DeprecationWarning. This workaround will be removed in a future release. (GH/1289, PR/2224).

• The xclim.indicators.atmos and xclim.indicators.land submodules have been refactored to move all conversion-based indicators to the new xclim.indices.converters module. This change is intended to improve code organization and clarity. Directly importing indicators that were previously accessible via atmos and land will still work but will emit a DeprecationWarning. This workaround will be removed in a future release. (GH/1289, PR/2224).

• xclim.indicators.atmos.tg has been refactored to xclim.indicators.convert.mean_temperature_from_max_and_min. Importing tg from xclim.indices.atmos or xclim.indicators.convert will still work but will emit a DeprecationWarning. This workaround will be removed in a future release. (GH/1289, PR/2224).

Internal changes

• Modified internal logic for xclim.testing.utils.default_testdata_cache to support mocking of pooch. (PR/2188).

• The xclim.indices.helpers module now uses an __all__ variable to explicitly define the public API of the module. (PR/2207).

• Viticulture indices are more heavily tested and employ type guarding to ensure that parameters passed are those of the expected types. (PR/2207).

• Fixed some tests relying on floating-point imprecision. Avoid numbagg on sensitive fitting tests. (PR/2228).

• Conversion indicators have been split from tests/test_atmos.py into new tests/test_converters.py. This is to ensure that conversion indicators are tested separately from other atmospheric indicators. (GH/1289, PR/2224).

• xclim.testing.utils.show_versions now uses the importlib.metadata library to more accurately gather dependency information. (PR/2229).

• Replaced the deprecated "time.week" grouping strings with da.time.dt.isocalendar().week in xclim.indices.stats.standardized_index functions. (PR/2230).

• xclim.indices.run_length.lazy_indexing moved to utils. (GH/2107, PR/2231).

• Updated the command-line configuration to address DeprecationWarning messages introduced in click v8.2.0 (changes remain compatible with click v8.1.0). (GH/2212, PR/2233).

Bug fixes

• Increase the tolerance in the tests of xclim.indices.standardized_groundwater_index (the standardized indices are sensitive to package versions because of the parameter optimization in scipy). (GH/2183, PR/2193).

• In xclim.indices._conversion.humidex and xclim.indices._conversion.vapor_pressure_deficit, add a converter to ensure hurs has '%' units. (PR/2209).

• Indices relying on units.to_agg_units(src, out, 'count') will not raise on a non-inferrable frequency and instead use the common default of “D”, as their docstring implies. (GH/2215, PR/2217).

• Fix spell_length_statistics and related functions for cases where thresh is a DataArray. (GH/2216, PR/2218).

• Addressed a noisy warning emitted by numpy in the xclim.indices.stats when performing a fit over data with missing values. (PR/2224).

• In the Canadian Forest Fire Weather Index System, values of 0 for both the Duff-Moisture code (DMC) and the Drought code (DC) will yield a 0 Build-Up index (BUI) instead of failing with division by zero error. (GH/2145, PR/2225).

• xclim.indices.generic.{doymax|doymin} now work with dask arrays. (GH/2107, PR/2231).

v0.57.0 (2025-05-22)

Contributors to this version: Éric Dupuis (@coxipi), Trevor James Smith (@Zeitsperre), Juliette Lavoie (@juliettelavoie), Pascal Bourgault (@aulemahal), Armin Hofmann (@HofmannGeo), Baptiste Hamon (@baptistehamon).

Announcements

• The xclim.sdba module has been split from xclim into the new package xsdba. Users must install xsdba from PyPI or conda-forge in order to maintain xclim.sdba functionality. Refer to the xsdba Migration Guide for more information. (GH/2074, PR/2099).

New indicators and features

• New indicator xclim.atmos.clearness_index computes the clearness_index (ratio of downwards solar radiation to extraterrestrial solar radiation). (PR/2140).

• New conversion indice xclim.indices.shortwave_downwelling_radiation_from_clearness_index provides the inverse of xclim.indices.clearness_index. (PR/2140).

• Added cooling_degree_days_approximation and heating_degree_days_approximation indices to compute the number of cooling and heating degree days with consideration for daily temperature cycles. (GH/1941, PR/2135).

• Added dtr in variables.yml. (GH/2146, PR/2147).

• Added Mahalanobis distance. (GH/2151, PR/2157).

• Support for DataTree objects in indicators. All non-empty nodes of the tree must contain all required variables, non-variable parameters are the same for all nodes. (GH/2127, PR/2144).

• Support for Dataset and DataTree objects in xclim.core.units.convert_units_to. Target units are passed as a mapping from variable name to units. Unmentioned variables are left untouched. (GH/2127, PR/2144).

Bug fixes

• Adjustments were made to the xclim[docs] installation recipe to ensure that the documentation builds correctly. The minimum required Python for rendering the documentation is now 3.11. (PR/2141).

• xclim.core.calendar.stack_periods was fixed to work with larger-than-daily source timesteps. Users are still encouraged to use da.resample(time=FREQ).construct('period') when possible. (GH/2148, PR/2150).

• Updated the create_ensemble docstring to avoid confusion about how the function aligns realizations with different calendars. (GH/2108, PR/2164).

• Fixed xclim.indices.run_length.find_events for multidimensional input using a cftime calendar. (PR/2172).

• xclim.ensembles.robustness_fractions will now return ‘0’ when all members are invalid (have missing values), avoiding faulty flags in robustness_categories. The latter was also modified to read the valid fraction and mask its output accordingly. (GH/2167, PR/2178).

Breaking changes

• xclim.sdba is now a convenience mapping that imports xsdba members instead of being its own submodule. This implies a number of breaking changes (GH/2074, PR/2099, PR/2181):

  • The sub-module xclim.sdba is no longer installed by default. Users must install xsdba separately using pip install xclim[extras] or {pip|conda} install xsdba.

  • Units handling: The “infer” context is no longer used in unit conversion in xclim.sdba functions.

  • The SDBA_EXTRA_OUTPUT global option can no longer be activated with xclim.set_options; Instead use xsdba.set_options where the option is now called EXTRA_OUTPUT.

  • The other global variable SDBA_ENCODE_CF was removed as it has been rendered obsolete.

• The previously deprecated functions sfcwind_2_uas_vas and uas_vas_2_sfcwind have been removed. (PR/2139).

• xclim.testing.open_dataset has been significantly modified and is now a thin wrapper for the nimbus testing data fetching class. It also no longer supports the dap_url parameter. Contributors are encouraged to consult the documentation pertaining to xclim.testing.utils.nimbus for the new approach to fetching testing data. (PR/2139).

• The xclim[dev] installation recipe now requires pytest-timeout for ending stalled tests. (PR/2176).

Internal changes

• Added a pre-commit hook for formatting BibTeX files and reformatted existing BibTeX files. (PR/2135).

• pre-commit hooks have been updated to their latest versions. (PR/2141).

• Updated a deprecated pathlib usage in the xclim documentation that was causing failures under Python 3.13. (PR/2141).

• Call signatures for most op arguments in xclim have been updated to use ‘Literal’ types instead of ‘str’. This change is intended to improve type checking and code clarity. (GH/1810, PR/2168).

• Changes to pylint configuration and to address low-hanging pylint issues. (PR/2170).

• The pyproject.toml file has been adjusted to leverage pytest-timeout with a maximum session time of 15 minutes and a maximum test duration of five (5) minutes. (PR/2176).

• Fixed a bug present in tests due to the netcdf4 engine found in test_wind.py that was causing failures when run in parallel. (GH/2179, PR/2176).

• Faster backend for run length computations where the time is unchunked. xclim.indices.run_length._cumsum_reset was rewritten to include the fast track which is called with xclim.indices.run_length._cumsum_reset_np. The slow track uses xclim.indices.run_length._cumsum_reset_xr which preserves all functionalities of the old xclim.indices.run_length._cumsum_reset. (PR/2136).

v0.56.0 (2025-03-27)

Contributors to this version: Trevor James Smith (@Zeitsperre), Hui-Min Wang (@Hem-W), Jack Kit-tai Wong (@jack-ktw), Adrien Lamarche (@LamAdr), Éric Dupuis (@coxipi), Jens de Bruijn (@jensdebruijn), Pascal Bourgault (@aulemahal), Sarah Gammon (@SarahG-579462).

New indicators

• Added standardized indicators for hydrology: xclim.land.standardized_streamflow_index and xclim.land.standardized_groundwater_index. (GH/1444, PR/1877).

Bug fixes

• Fix installation instructions in the Contributing guide. (GH/2088, PR/2089).

• Fixed parameter order in typing.cast() causing intermittent errors in solar_zenith_angle calculation. (GH/2097, PR/2098).

• xclim now uses the operator standard library instead of using xarray’s derived get_op function. A refactoring in xarray had changed the position of get_op which caused breakage. (GH/2113, PR/2114).

  • All other uses of xarray’s internal API were also removed. (PR/2116).

• Fixed an issue with star-annotated call signatures to maintain Python 3.10 compatibility. (PR/2116).

• Fixed to_agg_units that was converting units of temperature differences prematurely, without changing the values accordingly in the related DataArrays. (GH/2121, PR/2122).

• get_calendar now supports pandas.DatetimeIndex. xclim no longer uses xarray.cftime_range, which has been deprecated. (PR/2130).

• Avoid unnecessary time resampling in xclim.indices.stats.preprocess_standardized_index when freq is not None but the same as the input data. (GH/2111, PR/2112).

• Fixed an issue with fire_season that made it fail with datasets having non-uniform chunks. (GH/2129, PR/2132).

Breaking changes

• xclim no longer supports Python 3.10. The minimum required version is now Python 3.11. (PR/2082).

  • Reverted: Extended support for Python3.10 will continue until further notice. (PR/2100).

• The minimum versions of several key dependencies have been raised (numpy >=1.24.0; scikit-learn >=1.2.0; scipy >=1.11.0). (PR/2082).

• To ensure consistent naming of converters, the following indices have been deprecated with replacements. Changes will be made permanent in xclim v0.57.0. (GH/2039, PR/2117):

  • sfcwind_2_uas_vas: Use sfcwind_to_uas_vas instead.

  • uas_vas_2_sfcwind: Use uas_vas_to_sfcwind instead.

Internal changes

• black, isort, and nbqa have all been dropped from the development dependencies. (GH/1805, PR/2082).

• ruff has been configured to provide code formatting. (PR/2083):

  • The maximum line-length is now 120 characters.

  • Docstring formatting is now enabled.

  • Line endings in files now must be Unix-compatible (LF).

• The blackdoc pre-commit hook now only examines .rst and .md files. (PR/2083).

• The xclim documentation now has a support page for detailing the project’s usage and version support policies. (PR/2100).

• The indicator heat_wave_index now uses hot_spell_total_length index. The heat_wave_index index is identical to hot_spell_total_length and will be dropped in future versions. (GH/2031, PR/2102).

• Updated pre-commit hooks to their latest versions. (PR/2116).

• .. math:: tags in documentation are now properly indented with three (3) spaces. (PR/2128).

v0.55.1 (2025-02-26)

Contributors to this version: Éric Dupuis (@coxipi).

Bug fixes

• Re-allow the use of interp=”linear” in adjustments that use day-of-year grouping, group=Grouper(“time.dayofyear”, window). (PR/2087).

v0.55.0 (2025-02-17)

Contributors to this version: Juliette Lavoie (@juliettelavoie), Trevor James Smith (@Zeitsperre), Sascha Hofmann (@saschahofmann), Pascal Bourgault (@aulemahal), Éric Dupuis (@coxipi), Baptiste Hamon (@baptistehamon), Sarah Gammon (@SarahG-579462).

Breaking changes

• Missing value method “WMO” was modified to remove the criterion that the timeseries needs to be continuous (without holes). (PR/2058).

Announcements

• xclim now officially supports Python 3.13 (using numba v0.61.0). (GH/2022, PR/2054).

• xclim version 0.55.0 will be the last version to support Python 3.10. The next version will require Python 3.11 or higher. (PR/2054).

• xclim.sdba is in the process of being split into a separate package (xsdba) to help with the maintenance of the codebase as well as better support new SDBA functionality. Feature additions to the xclim.sdba module will no longer be accepted and should be made instead to xsdba. The developers aim to ensure a high level of interoperability between xclim and xsdba so that users are minimally impacted; A migration guide will be made available in a future release. (GH/1948, GH/2074, PR/2073).

New indicators

• Added xclim.land.holiday_snow_days to compute the number of days with snow on the ground during holidays (“Christmas Days”). (GH/2029, PR/2030).

• Added xclim.land.holiday_snow_and_snowfall_days to compute the number of days with snow on the ground and measurable snowfall during holidays (“Perfect Christmas Days”). (GH/2029, PR/2030).

• Added xclim.atmos.vapor_pressure_deficit to compute the vapor pressure deficit from temperature and relative humidity. (GH/1917, PR/2072).

New features and enhancements

• New function ensemble.partition.general_partition. (PR/2035).

• Added a new xclim.indices.generic.bivariate_count_occurrences function to count instances where operations and performed and validated for two variables. (PR/2030).

• xclim.testing.helpers.test_timeseries now accepts a calendar argument that is forwarded to xr.cftime_range. (PR/2019).

• New xclim.indices.fao_allen98, exporting the FAO-56 Penman-Monteith equation for potential evapotranspiration (GH/2004, PR/2067).

• Missing values method “pct” and “at_least_n” now accept a new “subfreq” option that allows to compute the missing mask in two steps. When given, the algorithm is applied at this “subfreq” resampling frequency first and then the result is resampled at the target indicator frequency. In the output, a period is invalid if any of its subgroup where flagged as invalid by the chosen method. (PR/2058, GH/1820).

• scipy.stats.rv_continuous instances can now be given directly as the dist argument in standardized_precipitation_index and standardized_precipitation_evapotranspiration_index indicators. This includes lmoments3 distributions when specifying method="PWM". (GH/2043, PR/2045).

• Time selection in xclim.core.calendar.select_time and the **indexer argument of indicators now supports day-of-year bounds given as DataArrays with spatial and/or temporal dimensions. (GH/1987, PR/2055).

• Maximum Spacing Estimation method for distribution fitting has been added to xclim.indices.stats.fit (GH/2078, PR/2077)

Bug fixes

• Fixed a bug in xclim.sdba.Grouper.get_index that didn’t correctly interpolate seasonal values (GH/2014, PR/2019).

• Fixed a bug where xclim.indicators.atmos.potential_evapotranspiration would return wrong results when hurs was provided in % (PR/2067).

• Fixed the default “op” argument of xclim.atmos.growing_season_end (GH/2056, PR/2080).

• Removed the useless “thresh” argument from xclim.atmos.precip_accumulation (GH/1763, PR/2080).

Internal changes

• Adjusted the TestOfficialYaml test to use a dynamic method for finding the installed location of xclim. (PR/2028).

• Adjusted two tests for better handling when running in Windows environments. (PR/2057).

• Refactor of the xclim.core.missing module, usage of the Missing objects has been broken. (PR/2058, PR/2055, PR/2076, GH/1820, GH/2000).

  • Objects are initialized with their options and then called with the data, input frequency, target frequency and indexer.

  • Subclasses receive non-resampled DataArray in their is_missing methods.

  • Subclasses receive the array of valid timesteps valid instead of null, the invalid ones.

  • MissingWMO now uses xclim.indices.helpers.resample_map which should greatly improve performance in a dask context.

• There is now a warning stating that fitkwargs are not employed when using the lmoments3 distribution. One exception is the use of ‘floc’ which is allowed with the gamma distribution. ‘floc’ is used to shift the distribution before computing fitting parameters with the lmoments3 distribution since loc=0 is always assumed in the library. (GH/2043, PR/2045).

• xclim now tracks energy usage and carbon emissions (“last run”, “average”, and “total”) during CI workflows using the eco-ci-energy-estimation GitHub Action. (PR/2046).

• xclim.sdba now emits a FutureWarning on import to inform users that the submodule is being deprecated. (PR/2073).

v0.54.0 (2024-12-16)

Contributors to this version: Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal), Éric Dupuis (@coxipi), Sascha Hofmann (@saschahofmann).

New features and enhancements

• Python 3.9 coding conventions have been dropped in favour of Python 3.10+ conventions. (PR/1988).

• xclim.indices.chill_unit now accepts a new argument positive_only to compute the daily positive chill units. (PR/2003).

Breaking changes

• The minimum required version of dask has been increased to 2024.8.1. (GH/1992, PR/1991).

• The docstrings of many xclim modules, classes, methods, and functions have been slightly adjusted to ensure stricter compliance with established numpy docstring conventions. (PR/1988).

• Using different time for ref and hist is now explicitly forbidden in many bias adjustment methods (e.g. EmpiricalQuantileMapping). Methods that combine ref, hist, and sim in the same map_groups also require that time arrays be equal in size. (GH/1903, PR/1995, PR/2013).

• xclim now uses a src layout for the codebase. Structure-dependent functions, documentation, and build commands have been adapted to reflect these changes. Developers will need to reinstall xclim using pip install -e .. (PR/1971).

• The call signature of xclim.indices.hot_spell_magnitude originally asked for an op argument that was not used. This argument has been removed. (PR/2018).

Bug fixes

• Fixed pickling issue with xclim.sdba.Grouper and other classes for usage with dask>=2024.11. (GH/1992, PR/1993).

• Fixed an issue with nimbus that was causing URL path components to be improperly joined. (PR/1997).

• base_kws_vars in MBCn is now copied inside the adjust function so that in-place changes do not change the dict globally. (PR/1999).

• Fixed a bug in the logic of xclim.testing.utils.load_registry that impacted the ability to load a registry.txt from a non-default repository. (PR/2001).

Internal changes

• Changed French translations with word “pluvieux” to “avec précipitations”. (GH/1960, PR/1994).

• Nan values in OTC and dOTC are only dropped and replaced at the lowest level so that the size of time arrays never changes on xarray levels. (PR/1995, PR/2013)

• streamflow entry replaced with "q" in variables.yml. (GH/1912, PR/1996).

• In order to address Error 403 (forbidden) requests when retrieving data from GitHub via ReadTheDocs, the nimbus class has been modified to use an overloaded fetch method that appends a modified User-Agent header to the request. (PR/2001).

• Addressed a very rare race condition that can happen if pytest is tearing down the test environment when running across multiple workers. (PR/1863).

• The numpydoc linting tool has been added to the development dependencies, linting checks, and the pre-commit configuration. (PR/1988).

• Added a more robust yamllint configuration to ensure that all YAML files are linted consistently. (PR/1971).

• Addressed a very rare singular matrix error that can happen in test_loess_smoothing_nan. (PR/2015).

• Addressed a handful of typing and call signature issues in the xclim codebase. (PR/2018).

CI changes

• Added the green-coding-solutions/eco-ci-energy-estimation GitHub Action to the workflows to establish energy and carbon usage of CI activity. (PR/1863).

• Various workflow security fixes: (PR/2023)

  • Simplified the bump-version.yml version string parsing to harden against template injection.

  • Further de-escalated privileges for most workflows.

v0.53.2 (2024-10-31)

Contributors to this version: Éric Dupuis (@coxipi), Pascal Bourgault (@aulemahal), Trevor James Smith (@Zeitsperre).

Breaking changes

• Due to a regression affecting symmetry of polyfit and polyval in xarray, xclim now requires xarray>=2023.11.0,!=2024.10.0 (see: pydata/xarray PR/9691. (PR/1978).

Bug fixes

• Fixed a bug where the units could be changed before a conversion of the magnitudes could occur. Conversion of units for multivariate DataArray is now properly handled in sdba.TrainAdjust and sdba.Adjust. (PR/1972).

• Fixed a units formatting bug with indicators that output “delta” Celsius degrees. (PR/1973).

• Corrected the "choices" of parameter op in the docstring of frost_free_spell_max_length. (PR/1977).

• Reorganised how Indicator subclasses can added arguments to the call signature. Injecting such arguments now works. For xclim’s subclasses, this bug only affected the indexer argument of indicators subclassing xc.core.indicator.IndexingIndicator. (PR/1981).

• All-nan slices are now treated correctly in method ExtremeValues. (GH/1982, PR/1983).

v0.53.1 (2024-10-21)

Contributors to this version: Trevor James Smith (@Zeitsperre).

Internal changes

• Fixed a few missing dependencies in the documentation build recipe that were causing errors in the CI workflow on ReadTheDocs. (PR/1970).

v0.53.0 (2024-10-17)

Contributors to this version: Adrien Lamarche (@LamAdr), Trevor James Smith (@Zeitsperre), Éric Dupuis (@coxipi), Pascal Bourgault (@aulemahal), Sascha Hofmann (@saschahofmann), David Huard (@huard).

Announcements

• xclim has now adopted the Scientific Python SPEC 0 conventions for its suggested dependency support schedule. (GH/1914, PR/1915).

• xclim has dropped support for Python 3.9 and adopted Python 3.10+ code styling conventions. (GH/1914, PR/1915).

New indicators

• New heat_spell_frequency, heat_spell_max_length and heat_spell_total_length : spell length statistics on a bivariate condition that uses the average over a window by default. (PR/1885, PR/1778).

• New hot_spell_max_magnitude : yields the magnitude of the most intensive heat wave. (PR/1926).

• New chill_portion and chill_unit : chill portion based on the Dynamic Model and chill unit based on the Utah model indicators. (GH/1753, PR/1909).

• New water_cycle_intensity : yields the sum of precipitation and actual evapotranspiration. (GH/410, PR/1947).

New features and enhancements

• New generic xclim.indices.generic.spell_mask that returns a mask of which days are part of a spell. Supports multivariate conditions and weights. Used in new generic index xclim.indices.generic.bivariate_spell_length_statistics that extends spell_length_statistics to two variables. (PR/1885).

• Indicator parameters can now be assigned a new name, different from the argument name in the compute function. (PR/1885).

• Add attribute units_metadata to outputs representing a difference between temperatures. This is needed to disambiguate temperature differences from absolute temperature. Changes affect indicators daily_temperature_range, daily_temperature_range_variability, extreme_temperature_range, interday_diurnal_temperature_range, and all degree-day indicators. Implemented using a new pint2cfattrs function to convert pint units to a dictionary of CF attributes. units2pint is also modified to support units_metadata attributes in DataArrays. Some SDBA properties and measures previously returning units of delta_degC will now return the original input DataArray units accompanied with the units_metadata attribute. (GH/1822, PR/1830).

• xclim.indices.run_length.windowed_max_run_sum accumulates positive values across runs and yields the maximum valued run. (PR/1926).

• Helper function xclim.indices.helpers.make_hourly_temperature to estimate hourly temperatures from daily min and max temperatures. (PR/1909).

• New global option resample_map_blocks to wrap all resample().map() code inside a xr.map_blocks to lower the number of dask tasks. Uses utility xclim.indices.helpers.resample_map and requires flox to ensure the chunking allows such block-mapping. Defaults to False. (PR/1848).

• xclim.indices.run_length.runs_with_holes allows to input a condition that must be met for a run to start and a second condition that must be met for the run to stop. (PR/1778).

• New generic compute function xclim.indices.generic.thresholded_events that finds events based on a threshold condition and returns basic stats for each. See also: xclim.indices.run_length.find_events. (PR/1778).

• xclim.core.units.rate2amount and xclim.core.units.amount2rate can now also accept quantities (pint objects or strings), in which case the dim argument must be the time coordinate through which we can find the sampling rate. (PR/1778).

• xclim.indices.stats.standardized_index now supports a weekly resampling frequency. Only “standard” calendars using numpy’s datetime64 dtype are supported for this mode. (GH/1892, PR/1952)

Bug fixes

• Fixed rate2amount and amount2rate for sub-daily frequencies. (GH/1962, PR/1963).

• Added the liquid water equivalent thickness (“[length]”) to amount (“[mass]/[area]”) transformation to the hydro context (the inverse operation was already there). (PR/1963).

• Fixed a small inefficiency in _otc_adjust, and the standardize method of OTC/dOTC is now applied on individual variable. (PR/1890, PR/1896).

• Removed deprecated cells in the tutorial notebook sdba.ipynb. (PR/1895).

Breaking changes

• platformdirs is no longer a direct dependency of xclim, but pooch is required to use many of the new testing functions (installable via pip install pooch or pip install ‘xclim[dev]’). (PR/1889).

• The following previously-deprecated functions have now been removed from xclim : xclim.core.calendar.convert_calendar, xclim.core.calendar.date_range, xclim.core.calendar.date_range_like, xclim.core.calendar.interp_calendar, xclim.core.calendar.days_in_year, xclim.core.calendar.datetime_to_decimal_year. For guidance on how to migrate to alternatives, see the version 0.50.0 Breaking changes. (GH/1010, PR/1845).

• The transform argument of OTC/dOTC classes (and child functions) has been changed to normalization, and numIterMax has been changed to num_iter_max in xclim.core.utils.optimal_transport (PR/1896).

• xclim now requires numpy >=1.23.0 and scikit-learn >=1.1.0, as well as (optionally) ipython >=8.5.0, nbsphinx >=0.9.5, and matplotlib >=3.6.0. (GH/1914, PR/1915).

Internal changes

• The Ouranosinc/xclim-testdata repository has been restructured for better organization and to make better use of pooch and data registries for testing data fetching (see: xclim-testdata PR/29). (PR/1889).

• The xclim.testing module has been refactored to make use of pooch with file registries. Several testing functions have been removed as a result: (PR/1889)

  • xclim.testing.utils.open_dataset now uses a pooch instance to deliver locally-stored datasets. Its call signature has also changed.

  • xclim now accepts more environment variables to control the behaviour of the testing setup functions. These include XCLIM_TESTDATA_BRANCH, XCLIM_TESTDATA_REPO_URL, and XCLIM_TESTDATA_CACHE_DIR.

  • xclim.testing.utils.get_file, xclim.testing.utils.get_local_testdata, xclim.testing.utils.list_datasets, and xclim.testing.utils.file_md5_checksum have been removed.

    • xclim.testing.utils.nimbus replaces much of this functionality. See the xclim documentation for more information.

• Many tests focused on evaluating the normal operation of remote file access tools under xclim.testing have been removed. (PR/1889).

• Setup and teardown functions that were found under tests/conftest.py have been optimised to reduce redundant calls when running pytest xclim. Some obsolete pytest fixtures have also been removed. (PR/1889).

• Many DeprecationWarning and FutureWarning messages emitted from xarray and pint have been addressed. (GH/1719, PR/1881).

• The code base has been adjusted to address many pylint-related warnings and errors. In some cases, casting was used to redefine some numpy and xarray objects. (GH/1719, PR/1881).

• xclim.core now uses absolute imports for clarity and some objects commonly used in the module have been moved to hidden submodules. (GH/1719, PR/1881).

• xclim.core.indicator.Parameter has a new attribute compute_name while xclim.core.indicator.Indicator lost its _variable_mapping. The translation from parameter (and variable) names in the indicator to the names on the compute function is now handled by Indicator._get_compute_args. (PR/1885).

• Adopted many linting and formatting suggestions from the Scientific Python repo-review tool: (PR/1910)

  • Applied several linting suggestions adopted by the scipy community.

  • Replaced isort with ruff-based import-sorting formatting.

  • Added formatting for Markdown files.

  • Added the bugbear, pyupgrade checks to the ruff formatter.

  • Adjusted mypy checks to be more standardized.

• Renamed annual deprecated frequency alias “A” to “Y” (PR/1930).

• The indices documentation now includes the members of xclim.indices.stats. (GH/1913, PR/1958).

• The default URL for fetching testing data is now set to the raw.githubusercontent.com mirror of xclim-testdata. (PR/1961).

• The upstream tox environment has been updated to not install the latest numpy until numba supports it. (PR/1961).

CI changes

• The pip cache, tox environments, and the xclim-testdata cache are now saved between workflow runs (using actions/cache) to reduce the time spent installing dependencies and downloading testing data. (PR/1906).

v0.52.2 (2024-09-16)

Contributors to this version: Pascal Bourgault (@aulemahal).

Bug fixes

• Fixed decimal_year import, fixed functions rate2amount, amount2rate, time_bnds and stack_periods for xarray version 2024.09.0. Removed datetime_to_decimal_year as the mirrored xarray function was replaced by ds.time.dt.decimal_year. (PR/1920).

v0.52.1 (2024-09-11)

Contributors to this version: Trevor James Smith (@Zeitsperre).

Bug fixes

• Adjusted the required base version of pyarrow to be v10.0.1 to address an environment resolution error on conda-forge. (PR/1918).

v0.52.0 (2024-08-08)

Contributors to this version: David Huard (@huard), Trevor James Smith (@Zeitsperre), Hui-Min Wang (@Hem-W), Éric Dupuis (@coxipi), Sarah Gammon (@SarahG-579462), Pascal Bourgault (@aulemahal), Juliette Lavoie (@juliettelavoie), Adrien Lamarche (@LamAdr).

Announcements

• xclim now supports both numpy versions >=1.20 and >=2.0. (GH/1785, PR/1814, PR/1870).

• xclim now needs cf_xarray>=0.9.3 but continues to support older versions of pint (<0.24) for compatibility reasons. (PR/1870).

New features and enhancements

• xclim.sdba.nbutils.quantile and its child functions are now faster. If the fastnanquantile library is installed, it is used as the backend for the computation of quantiles and yields even faster results. This dependency is now listed in the xclim[extras] recipe. (GH/1255, PR/1513).

• New multivariate bias adjustment class MBCn, giving a faster and more accurate implementation of the MBCn algorithm. (GH/1551, PR/1580).

• New multivariate bias adjustment classes OTC and dOTC. Requires the POT library which can be installed via the xclim[extras] recipe. (PR/1787).

• xclim is now compatible with pytest versions >=8.0.0. (PR/1632).

Breaking changes

• As of cf_xarray>=0.9.3, dimensionless quantities now use the "1" units attribute as specified by the CF conventions, previously an empty string was returned. (PR/1814).

• The definitions of the frost_free_season_start and frost_free_season_end have been slightly changed to be coherent with the frost_free_season_length and xclim’s notion of season in general. Indicator and indices signature have been adapted to the new conventions. (PR/1845).

• Season length indicators have been modified to return 0 for all cases where a proper season was not found, but the data is valid. Previously, a nan was given if neither a start nor an end were found, even if the data was valid, and a 0 was given if an end was found but without a valid start. (PR/1845).

Bug fixes

• Fixed the indexer bug in the xclim.indices.standardized_index_fit_params when multiple or non-array indexers are specified and fitted parameters are reloaded from netCDF. (GH/1842, PR/1843).

• Addressed a bug found in wet_spell_* indicators that was contributing to erroneous results. A new generic spell length statistic function (xclim.indices.generic.spell_length_statistics) is now used in wet and dry spells indicators. (GH/1834, PR/1838).

• Syntax for nan and inf was adapted to support numpy>=2.0. (PR/1814, GH/1785).

• The type in jitter now works with modern version of dask (>=2024.8.0). (PR/1864).

Internal changes

• Changed the French translation of “wet days” from “jours mouillés” to “jours pluvieux”. (GH/1825, PR/1826).

• In order to adapt to changes in pytest, the doctest fixtures have been split from the main testing suite and doctests are now run using $ python -c 'from xclim.testing.utils import run_doctests; run_doctests()'. (PR/1632).

• tox has been reconfigured to run doctests in a separate environment (tox -e doctests). (PR/1632).

• Added xclim.indices.generic.season to make season start, end, and length indices. Added a stat argument to xclim.indices.run_length.season to avoid returning a dataset. (PR/1845).

CI changes

• pip-tools (pip-compile) has been used to generate a lock file with hashes for the CI dependencies. (PR/1841).

• The main.yml workflow has been updated to use simpler trigger logic. (PR/1841).

• A workflow bug has been fixed that was causing multiple duplicate comments to be made on Pull Requests originating from forks. (PR/1841).

• The upstream.yml workflow was adapted to not install upstream Python dependencies using hashes (as it is impossible to install directly from GitHub sources using --require-hashes). (PR/1859).

• The tox-gh configuration has been set to handle the environment configurations on GitHub Workflows. The tox.ini file is also a bit more organized/consistent. (PR/1859).

v0.51.0 (2024-07-04)

Contributors to this version: Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal).

New features and enhancements

• Added the op keyword to the growing_season_{start|end} indices and indicators, allowing for customizable threshold operators using indices.generic.compare(). (GH/1794, PR/1796).

• xclim now separates the optional dependencies into dev and docs recipes. Both can be installed with the all option ($ python -m pip install xclim[all]). (PR/1806).

Bug fixes

• Units of degree-days computations with Fahrenheit input fixed to yield “°R d”. Added a new xclim.core.units.ensure_absolute_temperature method to convert from delta to absolute temperatures. (GH/1789, PR/1804).

• Clarified a typo in the docstring formula for xclim.indices.growing_season_length. (PR/1796).

Internal changes

• netcdf4 has been pinned below v1.7 for test stability reasons. (PR/1791).

• flake8-bandit-like checks have been enabled via ruff, with fixes for a few security-related issues. (PR/1806).

• xclim.testing.utils now employs more secure URL auditing checks. (PR/1806).

• CHANGES.rst has been renamed to CHANGELOG.rst, adhering to suggestions from the keepachangelog v.1.1.0 specifications. (PR/1823).

CI changes

• GitHub repository now uses Rulesets for branch protection. (PR/1790).

• Version bumping and project triage is now handled by the Ouranos Helper GitHub App. (PR/1790).

• bump-my-version has been updated to v0.23.0. (PR/1790).

• The Ouranos Helper GitHub App now provides verified commits. (GH/1811, PR/1812).

• Added the deptry package to the dev linter tools and linting workflows for performing dependency analyses. (PR/1806).

• Several linting tools have been updated to the latest versions and pinned. (PR/1806).

v0.50.0 (2024-06-17)

Contributors to this version: Trevor James Smith (@Zeitsperre), Éric Dupuis (@coxipi).

New features and enhancements

• New properties: Bivariate Spell Length (xclim.sdba.properties.bivariate_spell_length), Generalized Spell Lengths with an argument for window, and Specific Spell Lengths with window fixed to ‘1’ (xclim.sdba.properties.threshold_count, xclim.sdba.properties.bivariate_threshold_count). (PR/1758).

• New option normalize in sdba.measures.taylordiagram to obtain normalized Taylor Diagrams (divide standard deviations by standard deviation of the reference). (PR/1764).

Breaking changes

• pint has been pinned below v0.24 until xclim can be updated to support the latest version. (GH/1771, PR/1772).

• numpy has been pinned below v2.0.0 until xclim can be updated to support the latest version. (PR/1783).

• Calendar utilities that have an equivalent in xarray have been deprecated and will be removed in xclim v0.51.0. (GH/1010, PR/1761). This concerns the following members of xclim.core.calendar:

  • convert_calendarUse Dataset.convert_calendar, DataArray.convert_calendar or xr.coding.calendar_ops.convert_calendar instead.

    • If your code passes target as an array, first convert the source to the target’s calendar and then reindex the result to target.

    • If you were using the doy=True option, replace it with xc.core.calendar.convert_doy(source, target_cal).convert_calendar(target_cal).

    • "default" is no longer a valid calendar name for any xclim functions and will not be returned by get_calendar. Xarray has a use_cftime argument, xclim exposes it when the distinction is needed.

  • date_range : Use xarray.date_range instead.

  • date_range_like: Use xarray.date_range_like instead.

  • interp_calendar : Use Dataset.interp_calendar or xarray.coding.calendar_ops.interp_calendar instead.

  • days_in_year : Use xarray.coding.calendar_ops._days_in_year instead.

  • datetime_to_decimal_year : Use xarray.coding.calendar_ops._datetime_to_decimal_year instead.

Internal changes

• Synchronized tooling versions across pyproject.toml and tox.ini and pinned them to the latest stable releases in GitHub Workflows. (PR/1744).

• Fixed a few small spelling and grammar issues that were causing errors with codespell. Now ignoring SVG files. (PR/1769).

• Temporarily skipping the test_hawkins_sutton_smoke test due to strange behaviour with xarray. (PR/1769).

• Fixed some previously uncaught errors raised from recent versions of pylint and codespell. (PR/1772).

• Set the doctest examples to all use h5netcdf with worker-separated caches to load datasets. (PR/1772).

Bug fixes

• xclim.indices.{cold|hot}_spell_total_length now properly uses the argument window to only count spells with at least window time steps. (GH/1765, PR/1777).

• Addressed an error in xclim.ensembles._filters._concat_hist where remnants of a scenario selection were not being dropped properly. (PR/1780).

v0.49.0 (2024-05-02)

Contributors to this version: Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal), Juliette Lavoie (@juliettelavoie), David Huard (@huard), Gabriel Rondeau-Genesse (@RondeauG), Javier Diez-Sierra (@JavierDiezSierra), Sarah Gammon (@SarahG-579462), Éric Dupuis (@coxipi).

Announcements

• xclim has migrated its development branch name from master to main. (GH/1667, PR/1669).

New features and enhancements

• Indicator xclim.atmos.potential_evapotranspiration and indice xclim.indices.potential_evapotranspiration now accept a new value (DA02) for argument method implementing potential evapotranspiration based on Droogers and Allen (2002). (GH/1710, PR/1723).

• The documentation now uses the furo theme for Sphinx. This theme supports native “light” and “dark” modes, adaptive screen resolution, as well as provides a better navigation layout for pages housing long lists of entries (e.g. indices). (GH/1693, PR/1731).

• xclim.ensembles.ensemble_percentiles now takes a method argument, accepting one of: ‘interpolated_inverted_cdf’, ‘hazen’, ‘weibull’, ‘linear’ (default), ‘median_unbiased’, or ‘normal_unbiased’. (GH/1694, PR/1732).

• Distributions with negative values are directly fitted without need for an offset for distributions such as ‘gamma’ and ‘fisk’ in xclim.indices.standardized_precipitation_evapotranspiration_index. (GH/1477 PR/1720).

• xclim.indices.stats_fit_start gives an estimate of the loc parameter for ‘gamma’ and ‘fisk’ distributions. (GH/1477 PR/1720).

New indicators

• New snw_season_length and snd_season_length computing the duration between the start and the end of the snow season, both defined as the first day of a continuous period with snow above/under a threshold. Previous versions of these indicators were renamed snw_days_above and snd_days_above to better reflect what they computed : the number of days with snow above a given threshold (with no notion of continuity). (GH/1703, PR/1708).

• Added xclim.atmos.duff_moisture_code, part of the Canadian Forest Fire Weather Index System. It was already an output of the xclim.atmos.cffwis_indices, but now has its own standalone indicator. (GH/1698, PR/1712).

Breaking changes

• The previously deprecated functions xclim.sdba.processing.construct_moving_yearly_window and xclim.sdba.processing.unpack_moving_yearly_window have been removed. These functions have been replaced by xclim.core.calendar.stack_periods and xclim.core.calendar.unstack_periods. (PR/1717).

• The previously deprecated function xclim.ensembles.change_significance has been removed. (PR/1737).

• Indicators snw_season_length and snd_season_length have been modified. (GH/1703, PR/1708).

• The ‘hargeaves85’/’hg85’ method for the potential_evapotranspiration indicator and indice has been modified for precision and consistency with recent academic literature. (GH/1710, PR/1723).

• The __getitem__ method of xclim.core.indicator.Parameter instances has been removed. Accessing members of Parameters now uniquely uses dot notation. (PR/1721).

• The obsolete function wrapper for generating Indicators xclim.core.utils.wrapped_partial has been removed. (PR/1721).

• The default documentation theme has changed from sphinx-rtd-theme to furo; Several modifications to the documentation configuration and CSS overrides have been made to accommodate the changes. furo is now a docs dependency. (GH/1693, PR/1731).

• Estimation of parameters using _fit_start for gamma and fisk has been changed and can affect the results obtained with full-fledged (e.g. “ML”) methods. (GH/1477 PR/1720).

• Method APP in xclim.indices.standardized_precipitation_index and xclim.indices.standardized_precipitation_evapotranspiration_index now requires the user to impose a loc parameter through fitkwargs[‘floc’]. (GH/1477, PR/1720).

• Zero inflated distributions used in xclim.stats.standardized_index now appropriately use the probability of zeroes in the calibration data and not the entire dataset. (GH/1477 PR/1720).

Bug fixes

• Fixed a bug in sdba’s map_groups that prevented passing DataArrays with cftime coordinates if the sdba_encode_cf option was ‘True’. (GH/1673, PR/1674).

• Fixed bug in sdba where a loaded training dataset could not be used for adjustment. (GH/1678, PR/1679).

• Fixed bug with loess smoothing for an array full of NaNs. (PR/1699).

• Fixed and adapted time_bnds to the newest xarray. (PR/1700).

• Fixed “agreement fraction” in robustness_fractions to distinguish between negative change and no change. Added “negative” and “changed negative” fractions (GH/1690, PR/1711).

• make_criteria now skips columns with NaNs across all realizations. (PR/1713).

• Fixed bug where QuantileDeltaMapping adjustment was failing for seasonal grouping. (GH/1704, PR/1716).

• The codebase has been adjusted to address several (~400) mypy-related errors attributable to inaccurate function call signatures and variable name shadowing. (GH/1719, PR/1721).

• xclim.core.formatting.generate_indicator_docstring has been modified to ensure that the numpy-docstrings of all Indicators are consistent in their formatting. (PR/1731).

• Fixed documentation example for frequency adaptation with sdba. (GH/1740, PR/1742).

Internal changes

• Added “doymin” and “doymax” to the possible operations of generic.stats. Fixed a warning issue when op was “integral”. (PR/1672).

• Reorganized GitHub CI build matrices to run the doctests more consistently. (PR/1709).

• Removed the experimental numba and llvm dependency installation steps in the tox.ini file. Added numba@main to the upstream dependencies. (PR/1709).

• Added the tox-gh dependency to the development installation recipe. This will soon be required for running the tox test ensemble on GitHub Workflows. (PR/1709).

• Added the vulture static code analysis tool for finding dead code to the development dependency list and linters (makefile, tox and pre-commit hooks). (PR/1717).

• Added error message when using xclim.indices.stats.dist_method with nnlf and included note in docstring. (GH/1683, PR/1714).

• PEP8 rule N802 is now enabled in the ruff formatter. Function names should follow Snake case, with rare exceptions. (PR/1721).

• Linting dependencies have been updated to the latest versions and made consistent across environment.yml, pyproject.toml and tox.ini files. (PR/1717).

• Code styling for the documentation now uses sas (“light” theme) and lightbulb (“dark” theme) in order to ensure adequate contrast for code blocks. (PR/1731).

• Added several CSS overrides related to the HTML elements generated by xarray in the notebook-sourced documentation. (PR/1731).

v0.48.2 (2024-02-26)

Contributors to this version: Juliette Lavoie (@juliettelavoie).

Bug fixes

• Add measure to YAML validation schema (for building sdba properties) and allow skipping the YAML validation when building modules. (PR/1664).

v0.48.1 (2024-02-20)

Contributors to this version: Trevor James Smith (@Zeitsperre).

Bug fixes

• Fixed an issue with missing conda dependencies in the xclim documentation. (PR/1657).

• Adjusted the Mastodon publishing workflow. (PR/1657).

• Pinned nbconvert to address regressions when building the documentation. (PR/1658).

v0.48.0 (2024-02-19)

Contributors to this version: Juliette Lavoie (@juliettelavoie), Pascal Bourgault (@aulemahal), Trevor James Smith (@Zeitsperre), David Huard (@huard), Éric Dupuis (@coxipi), Dante Castro (@profesorpaiche), Gabriel Rondeau-Genesse (@RondeauG).

Announcements

• xclim no longer supports Python3.8. (GH/1268, PR/1565).

• xclim now officially supports Python3.12 (requires numba>=0.59.0). (PR/1613).

• xclim now adheres to the Semantic Versioning 2.0.0 specification. (GH/1556, PR/1569).

• The xclim repository now uses GitHub Discussions to offer help for users, coordinate translation efforts, and support general Q&A for the xclim community. The xclim Gitter room has been deprecated in favour of GitHub Discussions. (GH/1571, PR/1572).

• For secure correspondence, xclim now offers a PGP key for users to encrypt sensitive communications. For more information, see the SECURITY.md. (GH/1181, PR/1604).

New features and enhancements

• Added uncertainty partitioning method lafferty_sriver from Lafferty and Sriver (2023), which can partition uncertainty related to the downscaling method. (GH/1497, PR/1529).

• Validate YAML indicators description before trying to build module. (GH/1523, GH/1595, PR/1560, PR/1596, PR/1600).

• Support indexer keyword in YAML indicator description. (GH/1522, PR/1561).

• New xclim.core.calendar.stack_periods and unstack_periods for performing rolling(time=...).construct(..., stride=...) but with non-uniform temporal periods like years or months. They replace xclim.sdba.processing.construct_moving_yearly_window and unpack_moving_yearly_window which are deprecated and will be removed in a future release.

• New as_dataset options for xclim.set_options. When True, indicators will output Datasets instead of DataArrays. (GH/1257, PR/1625).

• Added new option for universal_thermal_climate_index calculation (wind_cap_min: bool) to cap low wind velocities to a minimum of 0.5 m/s following Bröde (2012) guidelines. (GH/1634, PR/1635).

• Added option never_reached to degree_days_exceedance_date to assign a custom value when the sum threshold is never reached. (GH/1459, PR/1647).

• Added option min_members to ensemble statistics to mask elements when the number of valid members is under a threshold. (GH/1459, PR/1647).

• Distribution instances can now be passed to the dist argument of most statistical indices. (PR/1644).

• Added a new xclim.indices.generic.select_rolling_resample_op function to allow for computing rolling statistics. (GH/1480, PR/1643).

• Add the possibility to use a group with a window in xc.sdba.processing.reordering. (PR/1566).

Breaking changes

• xclim base Python version has been raised to Python3.9. Python3.9+ coding conventions are now supported. (GH/1268, PR/1565).

• xclim base dependencies have been raised to pandas>=2.2.0 and xarray>=2023.11.0 to reflect changes to time frequency codes introduced in pandas==2.2.0. (GH/1534, PR/1565; see also: pydata/xarray GH/8394 and ). Many default frequency string outputs have been modified (:

  • ‘Y’ (year) -> ‘YE’ (year end). (see: pandas PR/55792).

  • ‘M’ (month) -> ‘ME’ (month end). (see: pandas PR/52064).

  • ‘Q’ (quarter) -> ‘QE’ (quarter end). (see: pandas PR/55553)

  • ‘A’ and ‘AS’ have been removed (use ‘YE’ and ‘YS’ instead). (see: pandas PR/55252). (‘YE’ is only supported for cftime data in xarray >= 2024.1.1).

  • ‘T’ (minute), ‘L’ (millisecond), ‘U’ (microsecond), and ‘N’ (nanosecond) -> ‘min’, ‘ms’, ‘us’, and ‘ns’. (see: pandas PR/54061).

• bump2version has been replaced with bump-my-version to bump the version number using configurations set in the pyproject.toml file. (GH/1557, PR/1569).

• xclim’s units registry and units formatting are now extended from cf-xarray. The exponent sign “^” is now never added in the units attribute. For example, square meters are given as “m2” instead of “m^2” by xclim. Both signs are still accepted as inputs. (GH/1010, PR/1590).

• yamale is now listed as a core dependency (was previously listed in the dev installation recipe). (GH/1595, PR/1596).

• Due to a licensing limitation, the calculation of empirical orthogonal function based on eofs (xclim.sdba.properties.first_eof) has been removed from xclim. (GH/1620, PR/1621).

• black formatting style has been updated to the 2024 stable conventions. isort has been added to the dev installation recipe. (PR/1626).

• The indice and indicator for winter_storm has been removed (deprecated since xclim>=0.46.0 in favour of snd_storm_days). (PR/1565).

• xclim has dropped support for scipy versions below v1.9.0 and numpy versions below v1.20.0. (PR/1565).

• For generic function select_resample_op and core.units.to_agg_units, operation “sum” will now return the same units as the input, and not implicitly be translated to an “integral”. (GH/1645, PR/1649).

• lmoments3 was removed as a dependency of xclim due to incompatible licensing (GPLv3 vs xclim’s Apache 2.0). Depending on the outcome of efforts to modify the licensing of lmoments3, this change may eventually be reverted. See Ouranosinc/lmoments3#12. See also the “frequency analysis” notebook for an example on how to continue using the probability weighted moments method for fitting distributions. (GH/1620, PR/1644).

Bug fixes

• Fixed passing missing=0 to xclim.core.calendar.convert_calendar. (GH/1562, PR/1563).

• Fixed wrong window attributes in xclim.indices.standardized_precipitation_index, xclim.indices.standardized_precipitation_evapotranspiration_index. (GH/1552, PR/1554).

• Fixed the daily case freq='D' for xclim.stats.preprocess_standardized_index (GH/1602, PR/1607).

• Several spelling mistakes have been corrected within the documentation and codebase. (PR/1576).

• Added missing xclim.ensembles.robustness_fractions and xclim.ensembles.robustness_categories in API doc section. (PR/1630).

• Fixed an issue that can occur when fetching the testing data and running tests on Windows systems. Adapted a few existing tests for Windows support. (PR/1648).

Internal changes

• The flake8 configuration has been migrated from setup.cfg to .flake8; setup.cfg has been removed. (PR/1569)

• The bump-version.yml workflow has been adjusted to bump the patch version when the last version is determined to have been a release version; otherwise, the build version is bumped. (GH/1557, PR/1569).

• The GitHub Workflows now use the step-security/harden-runner action to monitor source code, actions, and dependency safety. All workflows now employ more constrained permissions rule sets to prevent security issues. (PR/1577, PR/1578, PR/1597).

• Updated the CONTRIBUTING.rst directions to showcase the new versioning system. (GH/1557, PR/1573).

• The codespell library is now a development dependency for the dev installation recipe with configurations found within pyproject.toml. This is also now a linting step and integrated as a pre-commit hook. For more information, see the codespell documentation (PR/1576).

• Climate indicators search page now prioritizes the “official” indicators (atmos, land, seaIce and generic), virtual submodules can be added to search through checkbox option. (GH/1559, PR/1593).

• The OpenSSF StepSecurity bot has contributed some changes to the workflows and pre-commit. (GH/1181, PR/1606):

  • Dependabot has been configured to monitor the xclim repository for dependency updates. The actions-version-updater.yml workflow has been deprecated.

  • GitHub Actions are now pinned to their commit hashes to prevent unexpected changes in the future.

  • A new GitHub Workflow (workflow-warning.yml) has been added to warn maintainers when a forked repository has been used to open a Pull Request that modifies GitHub Workflows.

  • pylint has been configured to provide some overhead checks of the xclim codebase as well as run as part of xclim’s pre-commit hooks.

  • Some small adjustments to code organization to address pylint errors.

• dev formatting tools (black, blackdoc, isort) are now pinned to their pre-commit hook version equivalents in both pyproject.toml and tox.ini. (PR/1626).

• black, isort, and pyupgrade code formatters no longer target Python3.8 coding style conventions. (PR/1565).

• The GitHub Workflows now include builds to run tests against both Windows and MacOS. (PR/1648).

• prefetch is now available as a tox environment modifier in order to download the testing data before launching pytest (e.g. py3x-prefetch). This is required for running tests the first time on Windows if the testing data has not already been installed. (PR/1648).

• Removed step-security/harden-runner from the finish job as it does not work on container images lacking sudo access. (PR/1655).

v0.47.0 (2023-12-01)

Contributors to this version: Juliette Lavoie (@juliettelavoie), Pascal Bourgault (@aulemahal), Trevor James Smith (@Zeitsperre), David Huard (@huard), Éric Dupuis (@coxipi).

Announcements

• To circumvent issues stemming from changes to the frequency code convention in pandas v2.2, we have pinned xarray (< 2023.11.0) and pandas (< 2.2) for this release. This change will be reverted in xclim v0.48.0 to support the newer versions. (xarray>= 2023.11.0 and pandas>= 2.2).

• xclim v0.47.0 will be the last release supporting Python3.8.

New features and enhancements

• New functions xclim.ensembles.robustness_fractions and xclim.ensembles.robustness_categories. The former will replace xclim.ensembles.change_significance which is now deprecated and will be removed in xclim v0.49.0. (PR/1514).

• Added indicator ID to searched terms in the indicator search documentation page. (GH/1525, PR/1528).

Bug fixes

• Fixed a bug with n_escore=-1 in xclim.sdba.adjustment.NpdfTransform. (GH/1515, PR/1516).

• In the documentation, fixed the tooltips in the indicator search results. (GH/1524, PR/1527).

• If chunked inputs are passed to indicators mean_radiant_temperature and potential_evapotranspiration, sub-calculations of the solar angle will also use the same chunks, instead of a single one of the same size as the data. (GH/1536, PR/1542).

• Fix wrong attributes in xclim.indices.standardized_precipitation_index, xclim.indices.standardized_precipitation_evapotranspiration_index. (GH/1537, PR/1538).

Internal changes

• Pinned cf-xarray below v0.8.5 in Python3.8 installation to further extend legacy support. (PR/1519).

• pip check in conda builds in GitHub workflows have been temporarily set to always pass. (PR/1531).

• Configure RtD search rankings to emphasize notebooks and indicators over indices and raw source code. (PR/1526).

• Addressed around 100 very basic mypy typing errors and call signature errors. (PR/1532).

• Use the intermediate step _cumsum_reset_on_zero instead of rle which is sufficient in _boundary_run. (GH/1405, PR/1530).

v0.46.0 (2023-10-24)

Contributors to this version: David Huard (@huard), Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal), Éric Dupuis (@coxipi).

Announcements

• The default mechanism for computing the Mean Radiant Temperature, a part of the Universal Thermal Climate Index (UTCI) was broken in xclim v0.44.0 and v0.45.0. This has now been fixed by changing the default settings.

New indicators

• xclim.indices.snw_storm_days computes the number of days with snowfall amount accumulation above a given threshold (default: 10 Kg m-2). (PR/1505).

• Added xclim.indices.wind_power_potential to estimate the potential for wind power production given wind speed at the turbine hub height and turbine specifications, along with xclim.indices.wind_profile to estimate the wind speed at different heights based on wind speed at a reference height. (GH/1458, PR/1471).

New features and enhancements

• xclim now has a dedicated console command for prefetching testing data from xclim-testdata with branch options (e.g.: $ xclim prefetch_testing_data –branch some_development_branch). This command can be used to download the testing data to a local cache, which can then be used to run the testing suite without internet access or in “offline” mode. For more information, see the contributing documentation section for Updating Testing Data. (GH/1468, PR/1473).

• The testing suite now offers a means of running tests in “offline” mode (using pytest-socket to block external connections). This requires a local copy of xclim-testdata to be present in the user’s home cache directory and for certain pytest options and markers to be set when invoked. For more information, see the contributing documentation section for Running Tests in Offline Mode. (GH/1468, PR/1473).

• The SKIP_NOTEBOOKS flag to speed up docs builds is now documented. See the contributing documentation section Get Started! for details. (GH/1470, PR/1476).

• Refactored the indicators page with the addition of a search bar (GH/1433, PR/1454).

• Indicator xclim.indices.generic.stats now accepts any frequency (previously only daily). (PR/1498).

• Added argument “out_units” to select_resample_op to bypass limitations of to_agg_units in custom indicators. Also, added var to supported operations in to_agg_units. (PR/1498).

• adapt_freq_thresh argument was added to `sdba` training functions, to facilitate performing frequency adaptation appropriately in each map block. (PR/1407).

• Standardized indices (xclim.indices.standardized_precipitation_index and xclim.indices.standardized_precipitation_evapotranspiration_index) (GH/1270, GH/1416, GH/1474, PR/1311) were changed:

  • Optimized and noticeably faster calculation.

  • Can be computed in two steps: first compute fit parameters with xclim.indices.stats.standardized_index_fit_params, then use the output in the standardized indices functions.

  • The standardized index values are now clipped to ±8.21. This reflects the float64 precision of the computation when cumulative distributed function values are inverted to a normal distribution and avoids returning infinite values.

  • An offset parameter is now available to account for negative water balance values xclim.indices.standardized_precipitation_evapotranspiration_index.

Bug fixes

• Fixed an error in the pytest configuration that prevented copying of testing data to thread-safe caches of workers under certain conditions (this should always occur). (PR/1473). * Coincidentally, this also fixes an error that caused pytest to error-out when invoked without an active internet connection. Running pytest without network access is now supported (requires cached testing data). (GH/1468).

• Calling a sdba.map_blocks-wrapped function with data chunked along the reduced dimensions will raise an error. This forbids chunking the trained dataset along the distribution dimensions, for example. (GH/1481, PR/1482).

• Optimization of indicators huglin_index and biologically_effective_degree_days when used with dask and flox. As a side effect, the indice functions (i.e. under xclim.indices) no longer mask incomplete periods. The indicators’ output is unchanged under the default “check_missing” setting (GH/1494, PR/1495).

• Fixed xclim.indices.run_length.lazy_indexing which would sometimes trigger the loading of auxiliary coordinates. (GH/1483, PR/1484).

• Indicators snd_season_length and snw_season_length will return 0 instead of NaN if all inputs have a (non-NaN) zero snow depth (or water-equivalent thickness). (PR/1492, GH/1491)

• Fixed a bug in the pytest configuration that could prevent testing data caching from occurring in systems where the platform-dependent cache directory is not found in the user’s home. (GH/1468, PR/1473).

• Fix xclim.core.dataflags.data_flags variable name generation (PR/1507).

• Remove nonsensical stat=’average’ option for mean_radiant_temperature. (GH/1496, PR/1501).

Breaking changes

• pytest-socket is now a required development dependency for running “offline” tests or the “offline” configuration of the tox testing suite. This has been added to the dev installation recipe. (GH/1468, PR/1473).

• For better transparency and control in development, the tox configuration has been adapted to allow passing of markers directly to the pytest call. Positional arguments must be passed to tox after the – separator to select/deselect tests (e.g. 'tox -e py38 -- -m "not slow"'). (PR/1473).

• For better accuracy, the tox -e black recipe has been renamed to tox -e lint, as this configuration already included several other linting checks. (PR/1473).

• xclim.indices.winter_storm renamed to xclim.indices.snd_storm_days. (PR/1505).

• Default threshold in xclim.indices.snw_season_{start|length|end} changed form 20 kg m-2 to 4 kg m-2. (PR/1505).

• xclim development dependencies now include ruff. pycodestyle and pydocstyle have been replaced by ruff and removed from the dev installation recipe. (PR/1504).

• The mf_file call signature found in xclim.ensembles.create_ensemble (and xclim.ensembles._ens_align_dataset) has been removed (deprecated since xclim v0.43.0). (PR/1506).

• xclim.indices.standardized_precipitation_index and xclim.indices.standardized_precipitation_evapotranspiration_index will no longer accept two datasets (data and calibration data). Instead, a single dataset covering both the calibration and evaluation periods is expected. (GH/1270, PR/1311).

Internal changes

• Changed “degK” to “K” (used to designate Kelvin units). (PR/1475).

• Added a pytest marker (pytest.mark.requires_internet) to allow for skipping of tests that depend on remote network calls to function properly. (PR/1473).

• Added handling for pytest-socket’s SocketBlockedError in xclim.testing.open_dataset when attempting to fetch md5 validation files for cached testing data while explicitly disabling internet sockets. (GH/1468, PR/1473).

• Updated the testing data used in the analogs.ipynb notebook to use the testing data now found in Ouranosinc/xclim-testdata’s main branch. (xclim-testdata PR/26, PR/1473).

• Fixed an issue with automatic labelling that occurs when a Pull Request is made from a forked repository. (PR/1479).

• Changes to the .zenodo.json file no longer are marked as CI-related changes. (PR/1479).

• GitHub deployment workflows now employs use of deployment environments for workflow security and uses the Trusted Publisher feature to sign and publish the xclim wheel and source distributions. (PR/1469).

• Mastodon publishing now uses chuhlomin/render-template and a standard formatting markdown document to format Mastodon toots. (PR/1469).

• GitHub testing workflows now use Concurrency instead of the styfle/cancel-workflow-action to cancel redundant workflows. (PR/1487).

• The pkg_resources library has been replaced for the packaging library when version comparisons have been performed, and a few warning messages have been silenced in the testing suite. (GH/1489, PR/1490).

• New xclim.testing.helpers.assert_lazy context manager to assert the laziness of code blocks. (PR/1484).

• Added a fix for the deprecation warnings that importlib.resources throws, made backwards-compatible for Python3.8 with importlib_resources backport. (PR/1485).

• Added basic keywords on most indicators for easier searching in the docs. Extracted climate indicators API to its own page for faster loading. (PR/1502, GH/1433).

• nbstripout now removes ‘metadata.kernelspec’ in notebook cells. (PR/1407).

• Deprecation wrapper xclim.core.utils.deprecated are added to help with deprecation warnings. (PR/1505).

• xclim now uses ruff to format the codebase with make lint and pre-commit. flake8 is still used for the time being, solely to enforce docstring linting (with flake8-rst-docstrings) and alphabetical __all__ entries (with flake8-alphabetize). (PR/1504).

v0.45.0 (2023-09-05)

Contributors to this version: David Huard (@huard), Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal), Juliette Lavoie (@juliettelavoie), Gabriel Rondeau-Genesse (@RondeauG), Marco Braun (@vindelico), Éric Dupuis (@coxipi).

Announcements

• xclim now uses platformdirs to write xclim-testdata to the user’s cache directory. Dynamic paths are now used to cache data dependent on the user’s operating system. Developers can now safely delete the .xclim-testdata folder in their home directory without affecting the functionality of xclim. (PR/1460).

New indicators

• Variations of already existing indices: xclim.indices.snd_max and xclim.indices.frost_free_spell_max_length. (PR/1443, GH/1386).

New features and enhancements

• Added ensembles.hawkins_sutton method to partition the uncertainty sources in a climate projection ensemble. (GH/771, PR/1262), along with a notebook example. (PR/1466).

• New function xclim.core.calendar.convert_doy to transform day-of-year data between calendars. Also accessible from convert_calendar with doy=True. (GH/1283, PR/1406).

• New xclim.units.declare_relative_units to enable relative unit checks. This was applied to most “generic” indices. (PR/1414).

• Added new function xclim.sdba.properties.std to calculate the standard deviation of a variable over all years at a given time resolution. (PR/1445).

• Amended the documentation of xclim.sdba.properties.trend to document already existing functionality of calculating the return values of scipy.stats.linregress. (PR/1445).

• Add support for setting optional variables through the ds argument. (GH/1432, PR/1435).

• New xclim.core.calendar.is_offset_divisor to test if a given freq divides another one evenly (PR/1446).

• Missing value objects now support input timeseries of quarterly and yearly frequencies (PR/1446).

• Missing value checks enabled for all “generic” indicators (return_level, fit and stats) (PR/1446).

Bug fixes

• Fix kldiv docstring so the math formula renders to HTML. (GH/1408, PR/1409).

• Fix the registry entries of “generic” indicators. (GH/1423, PR/1424).

• Fix jetstream_metric_woollings so it uses the vertical coordinate identified by cf-xarray, instead of pressure (GH/1421, PR/1422).

  • Add logic to handle coordinates in decreasing order, or for longitudes defined from 0-360 instead of -180 to 180. (GH/1429, PR/1430).

• Fix virtual indicator attribute assignment causing individual indicator’s realm to be ignored. (GH/1425, PR/1426).

• Fixes the raise_flags argument of xclim.core.dataflags.data_flags so that an Exception is only raised when some checkups fail. (GH/1456, PR/1457).

• Fix xclim.indices.generic.get_zones so that bins can be given as input without error. (PR/1455).

Internal changes

• Tolerance thresholds for error in test_stats::test_fit have been relaxed to allow for more variation in the results. Previously untested *_moving_yearly_window functions are now tested. (GH/1400, PR/1402).

• Increased the guess of number of quantiles needed in ExtremeValues. (PR/1413).

• Tolerance thresholds for error in test_processing::test_adapt_freq have been relaxed to allow for more variation in the results. (GH/1417, PR/1418).

• Added "streamflow" to the list of known variables. (PR/1431).

• Refactoring of index backend calculations. (PR/1443, GH/1386):

  • Use xclim.indices.generic.select_resample_op for {tg|tn|tx}_{max|mean|min} , max_1day_precipitation_amount, {snw|snd}_max

  • Directly use {cold|hot}_spell_max_length in maximum_consecutive_{frost|tx}_days

  • xclim.indices.generic.select_resample_op now gives an output with the correct units (xclim.core.units.to_agg_units is used internally).

• Shuffle autogenerated documentation files into distinct folders that can be easily cleaned using Makefile. (PR/1449).

• Some docstring adjustments to existing classes. (PR/1449).

• The pre-commit dependency identify now associates Jupyter Notebooks as JSON files. pre-commit is now set to ignore JSON-formatting of notebooks. (PR/1449).

• Added a helper module _finder in the notebooks folder so that the working directory can always be found, with redundancies in place to prevent scripts from failing if the helper file is not found. (PR/1449).

• Added a manual cache-cleaning workflow (based on GitHub cache-cleaning example), triggered when a branch has been merged. (PR/1462).

• Added a workflow for posting updates to the xclim Mastodon account (using cbrgm/mastodon-github-action, triggered when a new version is published. (PR/1462).

• Refactor base indicator classes and fix misleading inheritance of return_level. (GH/1263, PR/1446).

Breaking changes

• Fix and adapt percentile_doy for an error raised by xarray > 2023.7.0. (GH/1417, PR/1450).

• integral replaces prod and delta_prod as possible input in xclim.core.units.to_agg_units (PR/1443, GH/1386).

v0.44.0 (2023-06-23)

Contributors to this version: Éric Dupuis (@coxipi), Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal), Ludwig Lierhammer (@ludwiglierhammer), David Huard (@huard).

Announcements

• xclim: xarray-based climate data analytics has been published in the Journal of Open Source Software (DOI:10.21105/joss.05415). Users can now make use of the Cite this repository button in the sidebar for academic purposes. Many thanks to our core developers and user base for their fine contributions over the years! (GH/95, PR/250).

• xclim now officially supports Python3.11. (PR/1388).

New indicators

• Several new indices and indicators:

  • snowfall_{frequency | intensity} for calculating the {percentage of | mean snowfall intensity on} days with snowfall above a threshold. (GH/1352, PR/1358)

  • {sfcWind | sfcWindmax}_{max | mean | min} for calculating the {max | mean | min} daily {mean | max} wind speed. (GH/1352, PR/1358)

  • {precip | liquid_precip | solid_precip}_average} for calculating the mean daily {total precipitation | liquid precipitation | solid precipitation } amount. (GH/1352, PR/1358)

  • {cold | dry}_spell_max_length for calculating maximum length of {cold | dry} spell events. (GH/1352, PR/1359).

  • dry_spell_frequency for calculating total number of dry spells. (GH/1352, PR/1359).

  • hardiness_zones with supported methods “usda” (USA) and “anbg” (Australia) for calculating hardiness classifications from climatologies. (GH/1290, PR/1396).

• New indicator late_frost_days for calculating the number of days where the daily minimum temperature is below a threshold over a given time period. (GH/1352, PR/1361).

New features and enhancements

• xclim.sdba.processing.escore performance was improved with a faster runtime (PR/1360).

• New generic function (flux_and_rate_converter) converting flux to a rate (and vice-versa) using a density. snw_to_snd and snd_to_snw were refactored using this function. (GH/1352, PR/1358)

• New function (prsn_to_prsnd) to convert snowfall flux ([mass] / [area] / [time]) to snowfall rate ([length] / [time]) using snow density ([mass] / [volume]). (GH/1352, PR/1358)

• New variables: Snowfall rate prsnd and surface maximum wind speed sfcWindmax. (GH/1352, PR/1358).

• Docstring for freq links to pandas offset aliases documentation. (GH/1310, PR/1392).

• New function xclim.indces.run_length.extract_events for determining runs whose starting and stopping points are defined through run length conditions. (PR/1256).

• Stats functions frequency_analysis now takes method parameter to select other fitting methods such as PWM or MOM. (GH/1168, PR/1398).

• xclim.indices.frost_days now accepts an **indexer parameter for calculating frost days over a temporal subset of the given dataset. (GH/1352, PR/1361).

• New function xclim.indices.generic.get_zones attributing a histogram bin index (a zone) to each value in an input array. (GH/1290, PR/1396).

Bug fixes

• Fixed a bug in xclim.core.calendar.time_bnds when using DataArrayResample objects, caused by an upstream change in xarray 2023.5.0. (GH/1368, PR/1377).

• ensembles.change_significance will returns NaNs when the input values are all NaNs, instead of failing. (GH/1379, PR/1380).

• Accelerated import of xclim by caching the compilation of guvectorize functions. (PR/1378).

• Fixed many issues with xclim.indices.helpers.cosine_of_solar_zenith_angle, the signature changed. (GH/1110, PR/1399).

Internal changes

• In order to ensure documentation can be rebuilt at a later time, errors raised by sphinx linkcheck are now set to be ignored when building the documentation. (PR/1375).

• With the publication of xclim, the code repository now offers a CITATION.cff configuration for users to properly cite the software (APA formatted and raw BibTeX) for academic purposes. (GH/95, PR/250).

• Logging messages emitted when redefining units via pint (caused by logging interactions with dependencies) have been silenced. (GH/1373, PR/1384).

• Fixed some annotations and dev recipe dependencies issues to allow for the development of xclim inside a python3.11 environment. (GH/1376, PR/1381).

• The deprecated mamba-org/provision-with-micromamba GitHub Action has been replaced with mamba-org/setup-micromamba. (PR/1388).

• xclim GitHub CI workflows now run builds against Python3.11. (PR/1388).

• In indices, verify that all parameters of type Quantified that have a default value have their dimension declared. (GH/1293, PR/1393).

• Updated roy_extremeprecip_2021 to the newly published paper. (PR/1394).

• Two new GitHub CI Actions have been added to the existing Workflows (PR/1390):

  • actions/add-to-project: Automatically adds issues to the xclim project.

  • saadmk11/github-actions-version-updater: Updates GitHub Action versions in all Workflows (triggered monthly).

• Added method parameter to frequency_analysis and fa. (GH/1168, PR/1398).

Breaking changes

• Signature of hot_spell_{frequency | max_length | total_length} : thresh_tasmax modified to thresh. (GH/1352, PR/1359).

v0.43.0 (2023-05-09)

Contributors to this version: Trevor James Smith (@Zeitsperre), Ludwig Lierhammer (@ludwiglierhammer), Pascal Bourgault (@aulemahal), Juliette Lavoie (@juliettelavoie), Alexis Beaupré (@Beauprel), Éric Dupuis (@coxipi).

Announcements

• xclim has passed the peer-review process and been officially accepted as a project associated with both pyOpenSci and PANGEO. Additionally, xclim has been accepted to be published in the Journal of Open Source Software. Our review process can be consulted here: PyOpenSci Software Review. (PR/1350).

New features and enhancements

• New xclim.sdba measure xclim.sdba.measures.taylordiagram. (PR/1360).

New indicators

• ensembles.change_significance now supports the Brown-Forsythe test. (PR/1292).

Bug fixes

• Fixed a bug in the pyproject.toml configuration that excluded the changelog (CHANGES.rst) from the packaged source distribution. (PR/1349).

• When summing an all-NaN period with resample, xarray v2023.04.0 now returns NaN, whereas earlier versions returned 0. This broke fraction_over_precip_thresh, but is now fixed. (PR/1354, GH/1337).

• In xclim.sdba’s Quantile Delta Mapping algorithm, the quantiles of the simulation to adjust were computed slightly differently than when creating the adjustment factor. The xclim.sdba.utils.rank function has been fixed to return “percentage-ranks” (quantiles) in the proper range. (GH/1334, PR/1355).

• The radiation converters (longwave_upwelling_radiation_from_net_downwelling and shortwave_upwelling_radiation_from_net_downwelling) were hard-coded to redefine output units as W m-2, regardless of input units, so long as unit dimensions checks cleared. Units are now set directly from inputs. (GH/1365, PR/1366).

Breaking changes

• Many previously deprecated indices and indicators have been removed from xclim (PR/1318), with replacement indicators suggested as follows:

  • xclim.indicators.atmos.first_day_above -> xclim.indicators.atmos.first_day_{tn | tg | tx}_above

  • xclim.indicators.atmos.first_day_below -> xclim.indicators.atmos.first_day_{tn | tg | tx}_below

  • xclim.indicators.land.continuous_snow_cover_end -> xclim.indicators.land.snd_season_end

  • xclim.indicators.land.continuous_snow_cover_start -> xclim.indicators.land.snd_season_start

  • xclim.indicators.land.fit -> xclim.indicators.generic.fit

  • xclim.indicators.land.frequency_analysis -> xclim.indicators.generic.return_level

  • xclim.indicators.land.snow_cover_duration -> xclim.indicators.land.snd_season_length

  • xclim.indicators.land.stats -> xclim.indicators.generic.stats

  • xclim.indices.continuous_snow_cover_end -> xclim.indices.snd_season_end

  • xclim.indices.continuous_snow_cover_start -> xclim.indices.snd_season_start

  • xclim.indices.snow_cover_duration -> xclim.indices.snd_season_length

• Several _private functions within xclim.indices.fire._cffwis that had been exposed publicly have now been rendered as hidden functions. Affected functions are: _day_length, _day_length_factor, _drought_code, _duff_moisture_code, _fine_fuel_moisture_code, _overwintering_drought_code. (PR/1159, PR/1369).

Internal changes

• The testing suite has been adjusted to ensure calls are made to existing functions using non-deprecated syntax. The volume of warnings emitted during testing has been significantly reduced. (PR/1318).

• In order to follow best practices and reduce the installed size of the xclim wheel, the tests folder containing the testing suite has been split from the package and placed in the top-level of the code repository. (GH/1348, PR/1349, suggested from PyOpenSci Software Review). Submodules that were previously called within xclim.testing.tests have been refactored as follows:

  • xclim.testing.tests.data → xclim.testing.helpers

  • xclim.testing.tests.test_sdba.utils → xclim.testing.sdba_utils

• Added a “Conventions” section to the README. (GH/1342, PR/1351).

• New helper function xclim.testing.helpers.test_timeseries for generating timeseries objects with specified variable names and units. (PR/1356).

• tox recipes and documentation now refer to the official build of SBCK, available on PyPI. (GH/1362, PR/1364).

• Excluded some URLs from sphinx linkcheck that were causing issues on ReadTheDocs. (PR/1364).

• Tagged versions of xclim-testdata now follow a calendar-based versioning scheme for easier determination of compatibility between xclim and testing data. (PR/1367, xclim-testdata discussion).

• flake8, pycodestyle, and pydocstyle checks have been significantly changed in order to clean up the code base of redundant # noqa markers. Linting checks for Makefile and tox recipes have been synchronized as well. (PR/1369).

• flake8 plugin flake8-alphabetize has been added to development recipes in order to check order of __all__ entries and Exceptions. (PR/1369).

• Corrected translations of cold_spell_{frequency | days} (PR/1372).

v0.42.0 (2023-04-03)

Contributors to this version: Trevor James Smith (@Zeitsperre), Juliette Lavoie (@juliettelavoie), Éric Dupuis (@coxipi), Pascal Bourgault (@aulemahal).

Announcements

• xclim now supports testing against tagged versions of Ouranosinc/xclim-testdata in order to support older versions of xclim. For more information, see the Contributing Guide for more details. (PR/1339).

• xclim v0.42.0 will be the last version to explicitly support Python3.8. (GH/1268, PR/1344).

New features and enhancements

• Two previously private functions for selecting a day of year in a time series when performing calendar conversions are now exposed. (GH/1305, PR/1317). New functions are:

  • xclim.core.calendar.yearly_interpolated_doy

  • xclim.core.calendar.yearly_random_doy

• scipy is no longer pinned below v1.9 and lmoments3>=1.0.5 is now a core dependency and installed by default with pip. (GH/1142, PR/1171).

• Fix bug on number of bins in xclim.sdba.properties.spatial_correlogram. (PR/1336)

• Add resample_before_rl argument to control when resampling happens in maximum_consecutive_{frost|frost_free|dry|tx}_days and in heat indices (in _threshold) (GH/1329, PR/1331)

• Add xclim.ensembles.make_criteria to help create inputs for the ensemble-reduction methods. (GH/1338, PR/1341).

New indicators

• Rain season index implemented (default parameters for West Africa). (GH/842, PR/1256)

Bug fixes

• Warnings emitted from regular usage of some indices (snowfall_approximation with method="brown", effective_growing_degree_days) due to successive convert_units_to calls within their logic have been silenced. (PR/1319).

• Fixed a bug that prevented the use of the sdba_encode_cf option with xarray 2023.3.0 (PR/1333).

• Fixed bugs in xclim.core.missing and xclim.sdba.base.Grouper when using pandas 2.0. (PR/1344).

Breaking changes

• The call signatures for xclim.ensembles.create_ensemble and xclim.ensembles._base._ens_align_dataset have been deprecated. Calls to these functions made with the original signature will emit warnings. Changes will become breaking in xclim>=0.43.0.(GH/1305, PR/1317). Affected variable:

  • mf_flag (bool) -> multifile (bool)

• The indice and indicator for last_spring_frost has been modified to use tasmin by default, reflecting its docstring and literature definition (GH/1324, PR/1325).

• following indices now accept the op argument for modifying the threshold comparison operator (PR/1325):

  • snw_season_length, snd_season_length, growing_season_length, frost_season_length, frost_free_season_length, rprcptot, daily_pr_intensity

• In order to support older environments, pandas is now conditionally pinned below v2.0 when installing xclim on systems running Python3.8. (PR/1344).

Bug fixes

• xclim.indices.run_length.last_run nows works when freq is not None. (GH/1321, PR/1323).

Internal changes

• Added xclim to the ouranos Zenodo community . (PR/1313).

• Significant documentation adjustments. (GH/1305, PR/1308):

  • The CONTRIBUTING page has been moved to the top level of the repository.

  • Information concerning the licensing of xclim is clearly indicated in README.

  • sphinx-autodoc-typehints is now used to simplify call signatures generated in documentation.

  • The SDBA module API is now found with the rest of the User API documentation.

  • HISTORY.rst has been renamed CHANGES.rst, to follow dask-like conventions.

  • Hyperlink targets for individual indices and indicators now point to their entries under API or Indices.

  • Module-level docstrings have migrated from the library scripts directly into the documentation RestructuredText files.

  • The documentation now includes a page explaining the reasons for developing xclim and a section briefly detailing similar and related projects.

  • Markdown explanations in some Jupyter Notebooks have been edited for clarity

• Removed Mapping abstract base class types in call signatures (dict variables were always expected). (PR/1308).

• Changes in testing setup now prevent test_mean_radiant_temperature from sometimes causing a segmentation fault. (GH/1303, PR/1315).

• Addressed a formatting bug that caused Indicators with multiple variables returned to not be properly formatted in the documentation. (GH/1305, PR/1317).

• tox now include sbck and eofs flags for easier testing of dependencies. CI builds now test against sbck-python @ master. (PR/1328).

• upstream CI tests are now run on push to master, at midnight, and can also be triggered via workflow_dispatch. Failures from upstream build will open issues using xarray-contrib/issue-from-pytest-log. (PR/1327).

• Warnings from set _version_deprecated within Indicators now emit FutureWarning instead of DeprecationWarning for greater visibility. (PR/1319).

• The Graphics section of the Usage notebook has been expanded upon while grammar and spelling mistakes within the notebook-generated documentation have been reduced. (GH/1335, PR/1338, suggested from PyOpenSci Software Review).

• The Contributing guide now lists three separate subsections to help users understand the gains from optional dependencies. (GH/1335, PR/1338, suggested from PyOpenSci Software Review).

v0.41.0 (2023-02-28)

Contributors to this version: Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal), Ludwig Lierhammer (@ludwiglierhammer), Éric Dupuis (@coxipi).

New features and enhancements

• New properties xclim.sdba.properties.decorrelation_length and xclim.sdba.properties.transition_probability. (PR/1252)

New indicators

• New indices and indicators for converting from snow water equivalent to snow depth (snw_to_snd) and snow depth to snow water equivalent (snd_to_snw) using snow density [kg/m^3]. (PR/1271).

• New indices and indicators for determining upwelling radiation (shortwave_upwelling_radiation_from_net_downwelling and longwave_upwelling_radiation_from_net_downwelling; CF variables rsus and rlus) from net and downwelling radiation (shortwave: rss and rsds; longwave: rls and rlds). (PR/1271).

• New indice and indicator {snd | snw}_season_{length | start | end} which generalize snow_cover_duration and continuous_snow_cover_{start | end} to allow using these functions with variable snw (PR/1275).

• New indice and indicator (dryness_index) for estimating soil humidity classifications for winegrowing regions (based on Riou et al. (1994)). (GH/355, PR/1235).

• ensembles.change_significance now supports Mann-whitney U-test and flexible realization. (PR/1285).

Breaking changes

• xclim testing default behaviours have been changed (GH/1295, PR/1297):

  • Running $ pytest will no longer use pytest-xdist distributed testing be default (can be set with -n auto|logical|#. Coverage is also no longer gathered/reported by default.

  • Running $ tox will now set pytest-xdist to use -n logical processes (with a max of 10).

  • Default behaviour for testing is to no longer always fetch xclim-testdata. If testdata is found in $HOME/.xclim_testing_data, files will be copied to individual processes, otherwise, will be fetched as needed.

• Environment variables evaluated when running pytest have been changed (GH/1295, PR/1297):

  • For testing against specific branches of xclim-testdata: MAIN_TESTDATA_BRANCH -> XCLIM_TESTDATA_BRANCH

  • The option to skip fetching of testdata (SKIP_TEST_DATA) has been removed

  • A new environment variable (XCLIM_PREFETCH_TESTING_DATA) is now available to gather xclim-testdata before running test ensemble (default: False).

  • Environment variables are now passed to tox on execution.

Bug fixes

• build_indicator_module_from_yaml now accepts a reload argument. When re-building a module that already exists, reload=True removes all previous indicator before creating the new ones. (GH/1192,:pull:1284).

• The test for french translations of official indicators was fixed and translations for CFFWIS indices, FFDI, KDBI, DF and Jetstream metric woollings have been added or fixed. (PR/1271).

• use_ufunc in windowed_run_count is now supplied with argument freq to warn users that the 1d method does not support resampling after run length operations (GH/1279, PR/1291).

• {snd|snw}_max_doy now avoids an error due to xr.argmax when there are all-NaN slices. (PR/1277).

Internal changes

• xclim has adopted PEP 517 and PEP 621 (pyproject.toml using the flit backend) to replace the legacy setup.py used to manage package organisation and building. Many tooling configurations that already supported the pyproject.toml standard have been migrated to this file. CI and development tooling documentation has been updated to reflect these changes. (PR/1278, suggested from PyOpenSci Software Review).

• Documentation source files have been moved around to remove some duplicated image files. (PR/1278).

• Coveralls GitHub Action removed as it did not support pyproject.toml-based configurations. (PR/1278).

• Add a remark about how xclim’s CFFWIS is different from the original 1982 implementation. (GH/1104, PR/1284).

• Update CI runs to use Python3.9 when examining upstream dependencies. Replace setup-conda action with provision-with-micromamba action. (PR/1286).

• Update CI runs to always use tox~=4.0 and the latest virtual machine images (now ubuntu-22.04). (PR/1288, PR/1297).

• SBCK installation command now points to the official development repository. (PR/1288).

• Some references in the BibTeX were updated to point to better resources. (PR/1288).

• Add a GitHub CI workflow for performing dependency security review scanning. (PR/1287).

• Grammar and spelling corrections were applied to some docstrings. (PR/1271).

• Added [radiation] ([power] / [area]) to list of defined acceptable units. (PR/1271).

• Updated testing data used to generate the atmosds dataset to use more reproducibly-converted ERA5 data, generated with the miranda Python package. (PR/1269).

• Updated testing dependencies to use pytest-xdist>=3.2, allowing for the new –dist=worksteal scheduler for distributing the pool of remaining tests across workers after individual workers have exhausted their own queues. (PR/1235).

• Adding infer context to the unit conversion in of the training of ExtremeValues. (PR/1299).

• Added sphinxcontrib-svg2pdfconverter for converting SVG graphics within documentation to PDF-compatible images. (PR/1296).

• README badges for supported Python versions and repository health have been added. (GH/1304, PR/1307).

v0.40.0 (2023-01-13)

Contributors to this version: Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal), David Huard (@huard), Juliette Lavoie (@juliettelavoie).

New features and enhancements

• Virtual modules can add variables to xclim.core.utils.VARIABLES through the new variables section of the yaml files. (GH/1129, PR/1231).

• xclim.core.units.convert_units_to can now perform automatic conversions based on the standard name of the input when needed. (GH/1205, PR/1206).

  • Conversion from amount (thickness) to flux (rate), using amount2rate and rate2amount.

  • Conversion from amount to thickness for liquid water quantities, using the new amount2lwethickness and lwethickness2amount. This is similar to the implicit transformations enabled by the “hydro” unit context.

  • Passing context='infer' will activate the “hydro” context if the source or the target are DataArrays with a standard name that is compatible, as decided by the new xclim.core.units.infer_context function.

• New generic indicator realm. Now holds indicators previously meant for streamflow analysis in the land realm: fit, return_level (previously freq_analysis) and stats. (GH/1130, PR/1225).

• Thresholds and other quantities passed as parameters of indicators can now be multi-dimensional DataArray`s. `xarray broadcasting mechanisms will apply. These parameters are now annotated as “Quantity” in the signatures (xclim.core.utils.Quantity), instead of “str” as before. Attributes where such thresholds where included will now read “<an array>” (french: “<une matrice>”) for these new cases. Multi-dimensional quantities are still largely unsupported, except where documented in the docstring. (GH/1093, PR/1236).

Breaking changes

• Rewrite of xclim.core.calendar.time_bnds. It should now be more resilient and versatile, but all cftime_* and cfindex_* functions were removed. (GH/74, PR/1207).

• hydro context is not always enabled, as it led to unwanted unit conversions. Unit conversion operations now need to explicitly declare the hydro context to support conversions from kg / m2 /s to mm/day. (GH/1208, PR/1227).

• Many previously deprecated indices and indicators have been removed from xclim (PR/1228), with replacement indices/indicators suggested as follows:

  • xclim.indicators.atmos.fire_weather_indexes → xclim.indicators.atmos.cffwis_indices

  • xclim.indices.freshet_start → xclim.indices.first_day_temperature_above

  • xclim.indices.first_day_above → xclim.indices.first_day_temperature_above

  • xclim.indices.first_day_below → xclim.indices.first_day_temperature_below

  • xclim.indices.tropical_nights → xclim.indices.tn_days_above

  • xclim.indices.generic.degree_days → xclim.indices.generic.cumulative_difference

• The following modules have been removed (PR/1228):

  • xclim.indices.fwi → functions migrated to xclim.indices.fire

  • xclim.subset (mock submodule) → functions migrated to clisops.core.subset

• Indicators standardized_precipitation_index and standardized_precipitation_evapotranspiration_index will now require pr_cal and wb_cal as keyword arguments only. (PR/1236).

• The internal object PercentileDataArray has been removed. (PR/1236).

• The xclim.testing.utils.get_all_CMIP6_variables and xclim.testing.utils.update_variable_yaml function were removed as the former was extremely slow and unusable. (PR/1258).

• The wind speed input of atmos.potential_evapotranspiration and atmos.water_budget was renamed to sfcWind (capital W) as this is the correct CMIP6 name. (PR/1258).

• Indicator land.stats, land.fit and land.freq_analysis are now deprecated and will be removed in version 0.43. They are being phased out in favor of generic indicators generic.stats, generic.fit and generic.return_level respectively. (GH/1130, PR/1225).

Bug fixes

• The weighted ensemble statistics are now performed within a context in order to preserve data attributes. (GH/1232, PR/1234).

• The make docs Makefile recipe was failing with an esoteric error. This has been resolved by splitting the linkcheck and docs steps into separate actions. (GH/1248. PR/1251).

• The setup step for pytest needed to be addressed due to the fact that files were being accessed/modified by multiple tests at a time, causing segmentation faults in some tests. This has been resolved by splitting functions into those that fetch or generate test data (under xclim.testing.tests.data) and the fixtures that supply accessors to them (under xclim.testing.tests.conftest). (GH/1238, PR/1254).

• Relaxed the expected output for test_spatial_analogs[friedman_rafsky] to support expected results from scikit-learn 1.2.0.

• The MBCn example in documentation has been fixed to properly imitate the source. (GH/1249, PR/1250).

• Streamflow indicators relying on indices defined in xclim.indices.stats were not checking input variable units. These indicators will now raise an error if input data units are not m^3/s. (GH/1130, PR/1225).

• Adjusted some documentation examples were not being rendered properly. (GH/1264, PR/1266).

Internal changes

• Minor adjustments to GitHub Actions workflows (newest Ubuntu images, updated actions version, better CI triggering). (PR/1221).

• Pint units context added to various operations, tests and Indicator attributes. (GH/1208, PR/1227).

• Updated article from Alavoine & Grenier (2022) within documentation. Many article reference URLs have been updated to use HTTPS where possible. (GH/1246, PR/1247).

• Added relevant variable dataflag checks for potential evaporation, convective precipitation, and air pressure at sea level. (PR/1241).

• Documentation restructured to include ReadMe page (as About) with some minor changes to documentation titles. (PR/1233).

• xclim development build now uses nbqa to effectively run black checks over notebook cells. (PR/1233).

• Some tox recipes (opt-slow, conda) are temporarily deactivated until a tox>=4.0-compatible tox-conda plugin is released. (PR/1258).

• A notebook (extendingxclim.ipynb) has been updated to remove mentions of obsolete xclim.subset module. (PR/1258).

• Merge of sdba documentation from the module and the rst files, some cleanup and addition of a section referring to GitHub issues. (PR/1230).

v0.39.0 (2022-11-02)

Contributors to this version: Trevor James Smith (@Zeitsperre), Abel Aoun (@bzah), Éric Dupuis (@coxipi), Travis Logan (@tlogan2000), Pascal Bourgault (@aulemahal).

New features and enhancements

• The general xclim description and ReadMe have been updated to reflect recent enhancements. (GH/1185, PR/1209).

• Documentation now supports intersphinx mapping references within code examples via sphinx-codeautolink and copying of code blocks via sphinx-copybutton. (PR/1182).

• Log-logistic distribution added to stats.py for use with standardized_precipitation_index and standardized_precipitation_evapotranspiration_index. (GH/1141, PR/1183).

• New option in many indices allowing for resampling in given periods after run_length operations. (GH/505, GH/916, GH/917, PR/1161).

• New base indicator class for sdba: StatisticalPropertyMeasure, those measures that also reduce the time (as a property does). (PR/1198).

• xclim.core.calendar.common_calendar to find the best calendar to use when uniformizing an heterogeneous collection of data. (PR/1217).

• xclim.ensembles.create_ensemble now accepts calendar=None, and uses the above function to guess the best one. It also now accepts cal_kwargs to fine tune the calendar conversion. (GH/1190, PR/1217).

• New data check : xclim.core.datachecks.check_common_time that ensures all inputs of multivariate indicators have the same frequency (and the same time anchoring for daily and hourly data). (GH/1111, PR/1217).

New indicators

• New indices first_day_temperature_{above | below} and indicators xclim.indices.first_day_{tn | tg | tx}_{above | below}. These indices/indicators accept operator (op) keyword for finer threshold comparison controls. (GH/1175, PR/1186).

• New generic indice cumulative_difference for calculating difference between values and thresholds across time (e.g. temperature: degree-days, precipitation: moisture deficit), with or without resampling/accumulating by frequency. (PR/1202).

• New spatial sdba properties and measures : spatial_correlogram, scorr and first_eof. The later needs the optional dependency eofs. (PR/1198).

Breaking changes

• Indices that accept lat or lon coordinates in their call signatures will now use cf-xarray accessors to gather these variables in the event that they are not explicitly supplied. (PR/1180). This affects the following:

  • huglin_index, biologically_effective_degree_days, cool_night_index, latitude_temperature_index, water_budget, potential_evapotranspiration

• cool_night_index now optionally accepts lat: str = "north" | "south" for calculating CNI over DataArrays lacking a latitude coordinate. (PR/1180).

• The offset value in standardized_precipitation_evapotranspiration_index is changed to better reproduce results in the reference library monocongo/climate_indices. (GH/1141, PR/1183).

• The first_day_below and first_day_above indices are now deprecated in order to clearly communicate the variables they act upon (GH/1175, PR/1186). The suggested migrations are as follows:

  • xclim.indices.first_day_above -> xclim.indices.first_day_temperature_above

  • xclim.indices.first_day_below -> xclim.indices.first_day_temperature_below

• The first_day_below and first_day_above atmos indicators are now deprecated in order to clearly communicate the variables they act upon (GH/1175, PR/1186). The suggested migrations are as follows:

  • xclim.atmos.first_day_above -> xclim.indices.first_day_{tn | tg | tx}_above

  • xclim.atmos.first_day_below -> xclim.indices.first_day_{tn | tg | tx}_below

• The degree_days generic indice has been deprecated in favour of cumulative_difference that is not limited only to temperature variables (GH/1200, PR/1202). The indices for atmos.{heating | cooling | growing}_degree_days are now built from generic.cumulative_difference.

• Running pytest now requires the pytest-xdist distributed testing dependency. This library has been added to the dev requirements and conda environment configuration. (PR/1203).

• Parameters reducer and window in xclim.indices.rle_statistics are now positional. (PR/1161).

• The relative_annual_cycle_amplitude and annual_cycle_amplitude have been rewritten to match the version defined in the VALUE project, outputs will change drastically (for the better) (PR/1198).

• English indicator metadata has been adjusted to remove frequencies from fields in the long_name of indicators. English indicators now have an explicit title and abstract. (GH/936, PR/1123).

• French indicator metadata translations are now more uniform and more closely follow agreed-upon grammar conventions, while also removing frequency fields in long_name_fr. (GH/936, PR/1123).

• The freshet_start indice is now deprecated in favour of first_day_temperature_above with thresh=’0 degC’, window=5. The freshet_start indicator is now based on first_day_temperature_above, but is otherwise unaffected. (GH/1195, PR/1196).

• Call signatures for several indices/indicators have been modified to optionally accept op for manually setting threshold comparison operators (GH/1194, PR/1197). The affected indices and indicators as follows:

  • hot_spell_max_length, hot_spell_frequency, cold_spell_days, cold_spell_frequency, heat_wave_index, warm_day_frequency (indice only), warm_night_frequency (indice only), dry_days, wetdays, wetdays_prop.

• Cleaner xclim.core.calendar.parse_offset : fails on invalid frequencies, return implicit anchors (YS -> JAN, Y -> DEC) and implicit is_start_anchored (D -> True). (GH/1213, , PR/1217).

Bug fixes

• The docstring of cool_night_index suggested that lat was an optional parameter. This has been corrected. (GH/1179, PR/1180).

• The mean_radiant_temperature indice was accessing hardcoded lat and lon coordinates from passed DataArrays. This now uses cf-xarray accessors. (PR/1180).

• Adopt (and adapt) unit registry declaration and preprocessors from cf-xarray to circumvent bugs caused by a refactor in pint 0.20. It also cleans the code a little bit. (GH/1211, PR/1212).

Internal changes

• The documentation build now relies on sphinx-codeautolink and sphinx-copybutton. (PR/1182).

• Many docstrings did not fully adhere to the numpy docstring format. Fields and entries for many classes and functions have been adjusted to adhere better. (PR/1182).

• The xdoctest namespace now provides access to session-scoped {variable}_dataset accessors, as well as a path_to_atmos_file object. These can be used for running doctests on all variables made in the pytest atmosds() fixture. (PR/1882).

• Upgrade CodeQL GitHub Action to v2. (GH/1188, PR/1189).

• New generic index first_day_threshold_reached is now used to compose all first_day_XYZ indices. (GH/1175, PR/1186).

• In order to reduce computation footprint, the GitHub CI full testing suite and doctests are now only run once a pull request has been reviewed and approved. The number of simultaneously triggered builds has also been reduced. (GH/1155, PR/1203).

• ReadTheDocs now only builds full documentation (including running notebooks) when pull requests are merged to the main branch. (GH/1155, PR/1203).

• xclim now leverages pytest-xdist to distribute tests among Python workers and significantly speed up the testing suite. (PR/1203).

• show_versions can now accept a list of dependencies so that other libraries can make use of this utility. (PR/1215).

• Pull Requests now are automatically tagged (CI, docs, indicators, and/or sdba) according to files modified using the GitHub Labeler Action. (PR/1214).

v0.38.0 (2022-09-06)

Contributors to this version: Pascal Bourgault (@aulemahal), Éric Dupuis (@coxipi), Trevor James Smith (@Zeitsperre), Abel Aoun (@bzah), Gabriel Rondeau-Genesse (@RondeauG), Dougie Squire (@dougiesquire).

New features and enhancements

• Adjustment methods of SBCK are wrapped into xclim when that package is installed. (GH/1109, PR/1115).

  • Wrapped SBCK tests are also properly run in the tox testing ensemble. (PR/1119).

• Method FAO_PM98 (based on Penman-Monteith formula) to compute potential evapotranspiration. (PR/1122).

• New indices for droughts: SPI (standardized precipitations) and SPEI (standardized water budgets). (GH/131, PR/1096).

• Most numba functions of sdba.nbutils now use the “lazy” compilation mode. This significantly accelerates the import time of xclim. (GH/1135, PR/1167).

• Statistical properties and measures from xclim.sdba are now Indicator subclasses (PR/1149).

New indicators

• xclim now has the McArthur Forest Fire Danger Index and related indices under a new xclim.indices.fire module. These indices are also available as indicators. (GH/1152, PR/1159)

• Drought-related indicators: SPI (standardized precipitations) and SPEI (standardized water budgets). (GH/131, PR/1096).

• ensembles.create_ensembles now accepts a realizations argument to assign a coordinate to the “realization” axis. It also accepts a dictionary as input so that keys are used as that coordinate. (PR/1153).

• ensembles.ensemble_percentiles, ensembles.ensemble_mean_std_max_min and ensembles.change_significance now support weights (PR/1151).

• Many generic indicators that compare arrays or against thresholds or now accept an op keyword for specifying the logical comparison operation to use in their calculations (i.e. {“>”, “>=”, “<”, “<=, “!=”, “==”}). (GH/389, PR/1157).

  • In order to prevent user error, many of these generic indices now have a constrain variable that prevents calling an indice with an inappropriate comparison operator. (e.g. The following will raise an error: op=">", constrain=("<", "<=")). This behaviour has been added to indices accepting op where appropriate.

Breaking changes

• scipy has been pinned below version 1.9 until lmoments3 can be adapted to the new API. (GH/1142, PR/1143).

• xclim now requires xarray>=2022.06.0. (PR/1151).

• Documentation CI (ReadTheDocs) builds will now fail if there are any misconfigured pages, internal link/reference warnings, or broken external hyperlinks. (GH/1094, PR/1131, GH/1139, PR/1140, PR/1160).

• Call signatures for generic indices have been reordered and/or modified to accept op, and optionally constrain, in many cases, and condition/conditional/operation has been renamed to op for consistency. (GH/389, PR/1157). The affected indices are as follows:

  • get_op, compare, threshold_count, get_daily_events, count_level_crossings, count_occurrences, first_occurrence, last_occurrence, spell_length, thresholded_statistics, temperature_sum, degree_days.

• All indices in xclim.indices.generic now use threshold in lieu of thresh for consistency. (PR/1157).

• Existing function xclim.indices.generic.compare can now be used to construct operations with op and constrain variables to allow for dynamic comparisons with user input handling. (GH/389, PR/1157).

• Two deprecated indices have been removed from xclim. (PR/1157):

  • xclim.indices._multivariate.daily_freezethaw_cycles -> Replaceable with the generic multiday_temperature_swing with thresh_tasmax=’0 degC’, thresh_tasmin=’0 degC’, window=1, and op=’sum’. The indicator version (xclim.atmos.daily_freezethaw_cycles) is unaffected.

  • xclim.indices.generic.select_time -> Was previously moved to xclim.core.calendar.

• The clix-meta indicator table parsing function (xclim.core.utils.adapt_clix_meta_yaml) has been adapted to support the new “op” operator handler. (PR/1157).

• Because they have been re-implemented as Indicator subclasses, statistical properties and measures of xclim.sdba no longer preserve attributes of their inputs by default. Use xclim.set_options(keep_attrs=True) to get the previous behaviour. (PR/1149).

• The xclim.indices.generic.extreme_temperature_range function has been fixed so it now does what its definition says. Results from xclim.indicators.cf.etr will change. (GH/1172, PR/1173).

• xclim now has a dedicated indices.fire submodule that houses all fire-related indices. The previous xclim.indices.fwi submodule is deprecated and will be removed in a future version. (GH/1152, PR/1159).

• The indicator xclim.indicators.atmos.fire_weather_indexes and indice xclim.indices.fire_weather_indexes have both been deprecated and renamed to cffwis_indices. Calls using the previous naming will be removed in a future version. (PR/1159).

• xclim now explicitly requires pybtex in order to generate documentation. (PR/1176).

Bug fixes

• Fixed saturation_vapor_pressure for temperatures in other units than Kelvins (also fixes relative_humidity_from_dewpoint). (GH/1125, PR/1127).

• Indicators that do not care about the input frequency of the data will not check the cell methods of their inputs. (PR/1128).

• Fixed the signature and docstring of heat_index by changing tasmax to tas. (GH/1126, PR/1128).

• Fixed a formatting issue with virtual indicator modules (_gen_returns_section) that was creating malformed Returns sections in sphinx-generated documentation. (PR/1131).

• Fix biological_effective_degree_days for non-scalar latitudes, when using method “gladstones”. (GH/1136, PR/1137).

• Fixed some extlink warnings found in sphinx and configured ReadTheDocs to use mamba as the dependency solver. (GH/1139, PR/1140).

• Fixed some broken hyperlinks to articles, users, and external documentation throughout the code base and jupyter notebooks. (PR/1160).

• Removed some artefact reference roles introduced in PR/1131 that were causing LaTeX builds of the documentation to fail. (GH/1154, PR/1156).

• Fix biological_effective_degree_days for non-scalar latitudes, when using method “gladstones”. (GH/1136, PR/1137).

• Fixed some extlink warnings found in sphinx and configured ReadTheDocs to use mamba as the dependency solver. (GH/1139, PR/1140).

• Fixed some broken hyperlinks to articles, users, and external documentation throughout the code base and jupyter notebooks. (PR/1160).

• Addressed a bug that was causing pylint to stackoverflow by removing it from the tox configuration. pylint should only be called from an active environment. (PR/1163)

• Fixed an issue with xclim.ensembles.kmeans_reduce_ensemble which caused it to fail when using dask arrays. (PR/1170).

• Addressed a bug that was causing pylint to stackoverflow by removing it from the tox configuration. pylint should only be called from an active environment. (PR/1163)

Internal changes

• Marked a test (test_release_notes_file_not_implemented) that can only pass when source files are available so that it can easily be skipped on conda-forge build tests. (GH/1116, PR/1117).

• Split a few YAML strings found in the virtual modules that regularly issued warnings on the code checking CI steps. (PR/1118).

• Function xclim.core.calendar.build_climatology_bounds now exposed via __all__. (PR/1146).

• Clarifications added to docstring of xclim.core.bootstrapping.bootstrap_func. (PR/1146).

• Bibliographic references for supporting scientific articles are now found in a bibtex file (docs/references.bib). These are now made available within the generated documentation using sphinxcontrib-bibtex. (GH/1094, PR/1131).

• Added information URLs to setup.py in order to showcase issue tracker and other sites on PyPI page (PR/1156).

• Configured the LaTeX build of the documentation to ignore the custom bibliographies, as they were redundant in the generated PDF. (PR/1158).

• Run length encoding (xclim.indices.run_length.rle) has been optimized. (GH/956, PR/1122).

• Added a sphinx-build -b linkcheck step to the tox-based “docs” build as well as to the ReadTheDocs configuration. (PR/1160).

• pylint is now setup to use a pylintrc file, allowing for more granular control of warnings and exceptions. Many errors are still present, so addressing them will need to occur gradually. (PR/1163).

• The generic indices count_level_crossings, count_occurrences, first_occurrence, and last_occurrence are now fully tested. (PR/1157).

• Adjusted the ANUCLIM indices by removing “ANUCLIM” from their titles, modifying their docstrings, and handling “op” input in a more user-friendly way. (GH/1055, PR/1169).

• Documentation for fire-based indices/indicators has been reorganized to reflect the new submodule structure. (PR/1159).

v0.37.0 (2022-06-20)

Contributors to this version: Abel Aoun (@bzah), Pascal Bourgault (@aulemahal), Trevor James Smith (@Zeitsperre), Gabriel Rondeau-Genesse (@RondeauG), Juliette Lavoie (@juliettelavoie), Ludwig Lierhammer (@ludwiglierhammer).

Announcements

• xclim is now compliant with PEP 563. Python3.10-style annotations are now permitted. (GH/1065, PR/1071).

• xclim is now fully compatible with xarray’s flox-enabled GroupBy and resample operations. (PR/1081).

• xclim now (properly) enforces docstring compliance checks using pydocstyle with modified numpy-style docstrings. Docstring errors will now cause build failures. See the pydocstyle documentation for more information. (PR/1074).

• xclim now uses GitHub Actions to manage patch version bumping. Merged Pull Requests that modify xclim code now trigger version-bumping automatically when pushed to the main development branch. Running $ bump2version patch within development branches is no longer necessary. (PR/1102).

New features and enhancements

• Add “Celsius” to aliases of “celsius” unit. (GH/1067, PR/1068).

• All indicators now have indexing enabled, except those computing statistics on spells. (GH/1069, PR/1070).

• A convenience function for returning the version numbers for relevant xclim dependencies (xclim.testing.show_versions) is now offered. (PR/1073).

  • A CLI version of this function is also available from the command line ($ xclim show_version_info). (PR/1073).

• New “keep_attrs” option to control the handling of the attributes within the indicators. (GH/1026, PR/1076).

• Added a notebook showcasing some simple examples of Spatial Analogues. (GH/585, PR/1075).

• create_ensembles now accepts a glob string to find datasets. (PR/1081).

• Improved percentile based indicators metadata with the window, threshold and climatology period used to compute percentiles. (GH/1047, PR/1050).

• New xclim.core.calendar.construct_offset, the inverse operation of parse_offset. (PR/1090).

• Rechunking operations in xclim.indices.run_length.rle are now synchronized with dask’s options. (PR/1090).

• A mention of the “missing” checks and options is added to the history attribute of indicators, where appropriate. (GH/1100, PR/1103).

Breaking changes

• xclim.atmos.water_budget has been separated into water_budget (calculated directly with ‘evspsblpot’) and water_budget_from_tas (original function). (PR/1086).

• Injected parameters in indicators are now left out of a function’s signature and will not be included in the history attribute. (PR/1086).

• The signature for the following Indicators have been modified (PR/1050):

  • cold_spell_duration_index, tg90p, tg10p, tx90p, tx10p, tn90p, tn10p, warm_spell_duration_index, days_over_precip_doy_thresh, days_over_precip_thresh, fraction_over_precip_doy_thresh, fraction_over_precip_thresh, cold_and_dry_days, warm_and_dry_days, warm_and_wet_days, cold_and_wet_days

• The parameter for percentile values is now named after the variable it is supposed to be computed upon. (PR/1050).

• pytest-runner has been removed as a dependency (it was never needed for xclim development). (PR/1074).

• xclim.testing._utils.py has been renamed to xclim.testing.utils.py for added documentation visibility. (PR/1074).

  • Some unused functions and classes (as_tuple, TestFile, TestDataSet) have been removed. (PR/1107).

New indicators

• universal_thermal_climate_index and mean_radiant_temperature for computing the universal thermal climate index from the near-surface temperature, relative humidity, near-surface windspeed and radiation. (GH/1060, PR/1062).

  • A new method ITS90 has also been added for calculating saturation water vapour pressure. (GH/1060, PR/1062).

Internal changes

• Typing syntax has been updated within pre-commit via isort. Pre-commit hooks now append from __future__ import annotations to all python module imports for backwards compatibility. (GH/1065, PR/1071)

• isort project configurations are now set in setup.cfg. (PR/1071).

• Many function docstrings, external target links, and internal section references have been adjusted to reduce warnings when building the docs. (PR/1074).

• Code snippets within documentation are now checked and reformatted to black conventions with blackdoc. A pre-commit hook is now in place to run these checks. (PR/1098).

• Test coverage statistic no longer includes coverage of the test files themselves. Coverage now reflects lines of usable code covered. (PR/1101).

• Reordered listed authors alphabetically. Promoted @bzah to core contributor. (PR/1105).

• Tests have been added for some functions in xclim.testing.utils.py; some previously uncaught bugs in list_input_variables, publish_release_notes, and show_versions have been patched. (GH/1078, PR/1107).

• A convenience command for installing xclim with key development branches of some dependencies has been added ($ make upstream). (GH/1088, PR/1092; amended in GH/1113, PR/1114).

  • This build configuration is also available in tox for local development purposes ($ tox -e pyXX-upstream).

Bug fixes

• Clean the bias_adjustement and history attributes created by xclim.sdba.adjust (e.g. when an argument is an xr.DataArray, only print the name instead of the whole array). (GH/1083, PR/1087).

• pydocstyle checks were silently failing in the pre-commit configuration due to a badly-formed regex. This has been adjusted. (PR/1074).

• adjust_doy_calendar was broken when the source or the target were seasonal. (GH/1097, GH/1091, PR/1099)

v0.36.0 (2022-04-29)

Contributors to this version: Pascal Bourgault (@aulemahal), Juliette Lavoie (@juliettelavoie), David Huard (@huard).

Bug fixes

• Invoking lazy_indexing twice in row (or more) using the same indexes (using dask) is now fixed. (GH/1048, PR/1049).

• Filtering out the nans before choosing the first and last values as fill_value in _interp_on_quantiles_1D. (GH/1056, PR/1057).

• Translations from virtual indicator modules do not override those of the base indicators anymore. (GH/1053, PR/1058).

• Fix mmday unit definition (factor 1000 error). (GH/1061, PR/1063).

New features and enhancements

• xclim.sdba.measures.rmse and xclim.sdba.measures.mae now use numpy instead of sklearn. This improves their performances when using dask. (PR/1051).

• Argument append_ends added to sdba.unpack_moving_yearly_window (PR/1059).

Internal changes

• Ipython was unpinned as version 8.2 fixed the previous issue. (GH/1005, PR/1064).

v0.35.0 (2022-04-01)

Contributors to this version: David Huard (@huard), Trevor James Smith (@Zeitsperre) and Pascal Bourgault (@aulemahal).

New indicators

• New indicator specific_humidity_from_dewpoint, computing specific humidity from the dewpoint temperature and air pressure. (GH/864, PR/1027)

New features and enhancements

• New spatial analogues method “szekely_rizzo” (PR/1033).

• Loess smoothing (and detrending) now skip NaN values, instead of propagating them. This can be controlled through the skipna argument. (PR/1030).

Bug fixes

• xclim.analog.spatial_analogs is now compatible with dask-backed DataArrays. (PR/1033).

• Parameter dmin added to spatial analog method “zech_aslan”, to avoid singularities on identical points. (PR/1033).

• xclim is now compatible with changes in xarray that enabled explicit indexing operations. (PR/1038, xarray PR).

Internal changes

• xclim now uses the check-json and pretty-format-json pre-commit checks to validate and format JSON files. (PR/1032).

• The few logging artifacts in the xclim.ensembles module have been replaced with warnings.warn calls or removed. (GH/1039, PR/1044).

v0.34.0 (2022-02-25)

Contributors to this version: Pascal Bourgault (@aulemahal), Trevor James Smith (@Zeitsperre), David Huard (@huard), Aoun Abel (@bzah).

Announcements

• xclim now officially supports Python3.10. (PR/1013).

Breaking changes

• The version pin for bottleneck (<1.4) has been lifted. (PR/1013).

• packaging has been removed from the xclim run dependencies. (PR/1013).

• Quantile mapping adjustment objects (EQM, DQM and QDM) and sdba.utils.equally_spaced_nodes will not add additional endpoints to the quantile range. With those endpoints, variables are capped to the reference’s range in the historical period, which can be dangerous with high variability in the extremes (ex: pr), especially if the reference doesn’t reproduce those extremes credibly. (GH/1015, PR/1016). To retrieve the same functionality as before use:

from xclim import sdba

# NQ is the the number of equally spaced nodes, the argument previously given to nquantiles directly.
EQM = sdba.EmpiricalQuantileMapping.train(
    ref, hist, nquantiles=sdba.equally_spaced_nodes(NQ, eps=1e-6), ...
)

• The “history” string attribute added by xclim has been modified for readability: (GH/963, PR/1018).

  • The trailing dot (.) was dropped.

  • None inputs are now printed as “None” (and not “<NoneType>”).

  • Arguments are now always shown as keyword-arguments. This mostly impacts sdba functions, as it was already the case for Indicators.

• The cell_methods string attribute appends only the operation from the indicator itself. In previous version, some indicators also appended the input data’s own cell_method. The clix-meta importer has been modified to follow the same convention. (GH/983, PR/1022)

New features and enhancements

• publish_release_notes now leverages much more regular expression logic for link translations to markdown. (PR/1023).

• Improve performances of percentile bootstrap algorithm by using xarray.map_block (GH/932, PR/1017).

Bug fixes

• Loading virtual python modules with build_indicator_module_from_yaml is now fixed on some systems where the current directory was not part of python’s path. Furthermore, paths of the python and json files can now be passed directly to the indices and translations arguments, respectively. (GH/1020, PR/1021).

Internal changes

• Due to an upstream bug in bottleneck’s support of virtualenv, tox builds for Python3.10 now depend on a patched fork of bottleneck. This workaround will be removed once the fix is merged upstream. (PR/1013, see: bottleneck PR/397).

  • This has been removed with the release of bottleneck version 1.3.4. (PR/1025).

• GitHub CI actions now use the deadsnakes python PPA Action for gathering the Python3.10 development headers. (PR/1013).

• The “is_dayofyear” attribute added by several indices is now a numpy.int32 instance, instead of python’s int. This ensures a THREDDS server can read it when the variable is saved to a netCDF file with xarray/netCDF4-python. (GH/980, PR/1019).

• The xclim git repository now offers Issue Forms for some general issue types.

v0.33.2 (2022-02-09)

Contributors to this version: Pascal Bourgault (@aulemahal), Juliette Lavoie (@juliettelavoie), Trevor James Smith (@Zeitsperre).

Announcements

• xclim no longer supports Python3.7. Code conventions and new features for Python3.8 (PEP 569) are now accepted. (GH/966, PR/1000).

Breaking changes

• Python3.7 (PEP 537) support has been officially deprecated. Continuous integration testing is no longer run against this version of Python. (GH/966, PR/1000).

Bug fixes

• Adjusted behaviour in dataflags.ecad_compliant to remove data_vars of invalids checks that return None, causing issues with dask. (PR/1002).

• Temporarily pinned ipython below version 8.0 due to behaviour causing hangs in GitHub Actions and ReadTheDocs. (GH/1005, PR/1006).

• indices.stats methods where adapted to handle dask-backed arrays. (GH/1007, :pull:`1011).

• sdba.utils.interp_on_quantiles, with extrapolation='constant', now interpolates the limits of the interpolation along the time grouping index, fixing a issue with “time.month” grouping. (GH/1008, PR/1009).

Internal changes

• pre-commit now uses Black 22.1.0 with Python3.8 style conventions. Existing code has been adjusted. (PR/1000).

• tox builds for Python3.7 have been deprecated. (PR/1000).

• Docstrings and documentation has been adjusted for grammar and typos. (PR/1000).

• sdba.utils.extrapolate_qm has been removed, as announced for xclim 0.33. (PR/1009).

v0.33.0 (2022-01-28)

Contributors to this version: Trevor James Smith (@Zeitsperre), Pascal Bourgault (@aulemahal), Tom Keel (@Thomasjkeel), Jeremy Fyke (@JeremyFyke), David Huard (@huard), Abel Aoun (@bzah), Juliette Lavoie (@juliettelavoie), Yannick Rousseau.

Announcements

• Deprecation: Release 0.33.0 of xclim will be the last version to explicitly support Python3.7 and xarray<0.21.0.

• xclim now requires yaml files to pass yamllint checks on Pull Requests. (PR/981).

• xclim now requires docstrings have valid ReStructuredText formatting to pass basic linting checks. (PR/993). Checks generally require:

  • Working hyperlinks and reference tags.

  • Valid content references (e.g. :py:func:).

  • Valid NumPy-formatted docstrings.

• The xclim developer community has now adopted the ‘Contributor Covenant’ Code of Conduct v2.1 (text). (GH/948, PR/996).

New indicators

• jetstream_metric_woollings indicator returns latitude and strength of jet-stream in u-wind field. (GH/923, PR/924).

New features and enhancements

• Features added and modified to allow proper multivariate adjustments. (PR/964).

  • Added xclim.sdba.processing.to_additive_space and xclim.sdba.processing.from_additive_space to transform “multiplicative” variables to the additive space. An example of multivariate adjustment using this technique was added to the “Advanced” sdba notebook.

  • xclim.sdba.processing.normalize now also returns the norm. xclim.sdba.processing.jitter was created by combining the “under” and “over” methods.

  • xclim.sdba.adjustment.PrincipalComponent was modified to have a simpler signature. The “full” method for finding the best PC orientation was added. (GH/697).

• New xclim.indices.stats.parametric_cdf function to facilitate the computation of return periods over DataArrays of statistical distribution parameters (GH/876, PR/984).

• Add copy parameter to percentile_doy to control if the array input can be dumped after computing percentiles (GH/932, PR/985).

• New improved algorithm for dry_spell_total_length, performing the temporal indexing at the right moment and with control on the aggregation operator (op) for determining the dry spells.

• Added properties.py and measures.py in order to perform diagnostic tests of sdba (GH/424, PR/967).

• Update how percentile_doy rechunk the input data to preserve the initial chunk size. This should make the computation memory footprint more predictable (GH/932, PR/987).

Breaking changes

• To reduce import complexity, select_time has been refactored/moved from xclim.indices.generic to xclim.core.calendar. (GH/949, PR/969).

• The stacking dimension of xclim.sdba.stack_variables has been renamed to “multivar” to avoid name conflicts with the “variables” property of xarray Datasets. (PR/964).

• xclim now requires cf-xarray>=0.6.1. (GH/923, PR/924).

• xclim now requires statsmodels. (GH/424, PR/967).

Internal changes

• Added a CI hook in .pre-commit-config.yaml to perform automated pre-commit corrections with GitHub CI. (PR/965).

• Adjusted CI hooks to fail earlier if lint checks fail. (PR/972).

• TrainAdjust and Adjust object have a new skip_input_checks keyword arg to their train and adjust methods. When True, all unit-, calendar- and coordinate-related input checks are skipped. This is an ugly solution to disappearing attributes when using xr.map_blocks with dask. (PR/964).

• Some slow tests were marked slow to help speed up the standard test ensemble. (PR/969).

  • Tox testing ensemble now also reports slowest tests using the --durations flag.

• pint no longer emits warnings about redefined units when the logging module is loaded. (GH/990, PR/991).

• Added a CI step for cancelling running workflows in pull requests that receive multiple pushes. (PR/988).

Bug fixes

• Fix mistake in the units of spell_length_distribution. (GH/1003, PR/1004)

v0.32.1 (2021-12-17)

Bug fixes

• Adjusted a test (test_cli::test_release_notes) that prevented conda-forge test ensemble from passing. (PR/962).

v0.32.0 (2021-12-17)

Contributors to this version: Pascal Bourgault (@aulemahal), Travis Logan (@tlogan2000), Trevor James Smith (@Zeitsperre), Abel Aoun (@bzah), David Huard (@huard), Clair Barnes (@clairbarnes), Raquel Alegre (@raquelalegre), Jamie Quinn (@JamieJQuinn), Maliko Tanguy (@malngu), Aaron Spring (@aaronspring).

Announcements

• Code coverage (coverage/coveralls) is now a required CI check for merging Pull Requests. Requirements are now:

  • No individual run may report <80% code coverage.

  • Some drop in coverage is now tolerable, but runs cannot dip below -0.25% relative to the main branch.

New features and enhancements

• Added an optimized pathway for xclim.indices.run_length functions when window=1. (PR/911, GH/910).

• The data input frequency expected by Indicator is now in the src_freq attribute and is thus controllable by subclassing existing indicators. (GH/898, PR/927).

• New **indexer keyword args added to many indicators, it accepts the same arguments as xclim.indices.generic.select_time, which has been improved. Unless otherwise specified, the time selection is done before any computation. (PR/934, GH/899).

• Rewrite of xclim.sdba.ExtremeValues, now fixed with a correct algorithm. It has not been tested extensively and should be considered experimental. (PR/914, GH/789, GH/790).

• Added days_over_precip_doy_thresh and fraction_over_precip_doy_thresh indicators to distinguish between WMO and ECAD definition of the Rxxp and RxxpTot indices. (GH/931, PR/940).

• Update xclim.core.utils.nan_calc_percentiles to improve maintainability. (PR/942).

• Added heat_index indicator. Added heat_index indicator. This is similar to humidex but uses a different dew point as well as heat balance equations which account for variables other than vapor pressure. (GH/807) and (PR/915).

• Added alternative method for xclim.indices.potential_evapotranspiration based on mcguinnessbordne05 (from Tanguay et al. 2018). (PR/926, GH/925).

• Added snw_max and snw_max_doy indicators to compute the maximum snow amount and the day of year of the maximum snow amount respectively. (GH/776, PR/950).

• Added index for calculating ratio of convective to total precipitation. (GH/920, PR/921).

• Added wetdays_prop indicator to calculate the proportion of days in a period where the precipitation is greater than a threshold. (PR/919, GH/918).

Breaking changes

• Following version 1.9 of the CF Conventions, published in September 2021, the calendar name “gregorian” is deprecated. core.calendar.get_calendar will return “standard”, even if the underlying cftime objects still use “gregorian” (cftime <= 1.5.1). (PR/935).

• xclim.sdba.utils.extrapolate_qm is now deprecated and will be removed in version 0.33. (PR/941).

• Dependency pint minimum necessary version is now 0.10. (PR/959).

Internal changes

• Removed some logging configurations in xclim.core.dataflags that were polluting python’s main logging configuration. (PR/909).

• Synchronized logging formatters in xclim.ensembles and xclim.core.utils. (PR/909).

• Added a helper function for generating the release notes with dynamically-generated ReStructuredText or Markdown-formatted hyperlinks (PR/922, GH/907).

• Split of resampling-related functionality of Indicator into new ResamplingIndicator and ResamplingIndicatorWithIndexing subclasses. The use of new (private) methods makes it easier to inject functionality in indicator subclasses. (GH/867, PR/927, PR/934).

• French translation metadata fields are now cleaner and much more internally consistent, and many empty metadata fields (e.g. comment_fr) have been removed. (PR/930, GH/929).

• Adjustments to the tox builds so that slow tests are now run alongside standard tests (for more accurate coverage reporting). (PR/938).

• Use xarray.apply_ufunc to vectorize statistical functions. (PR/943).

• Refactor of xclim.sdba.utils.interp_on_quantiles so that it now handles the extrapolation directly and to better handle missing values. (PR/941).

• Updated heating_degree_days and fraction_over_precip_thresh documentations. (GH/952, PR/953).

• Added an intersphinx mapping to xarray. (PR/955).

• Added a CodeQL security analysis GitHub CI hook on push to master and on Friday nights. (PR/960).

Bug fixes

• Fix bugs in the cf_attrs and/or abstract of continuous_snow_cover_end and continuous_snow_cover_start. (PR/908).

• Remove unnecessary keep_attrs from resample call which would raise an error in futur Xarray version. (PR/937).

• Fixed a bug in the regex that parses usernames in the history. (PR/945).

• Fixed a bug in xclim.indices.generic.doymax and xclim.indices.generic.doymin that prevented the use of the functions on multidimensional data. (PR/950, GH/951).

• Skip all missing values in xclim.sdba.utils.interp_on_quantiles, drop them from both the old and new coordinates, as well as from the old values. (PR/941).

• “degrees_north” and “degrees_east” (and their variants) are now considered independent units, so that pint and xclim.core.units.ensure_cf_units don’t convert them to “deg”. (PR/959).

• Fixed a bug in xclim.core.dataflags that would misidentify the “extra” variable to be called when running multivariate checks. (PR/957, GH/861).

v0.31.0 (2021-11-05)

Contributors to this version: Abel Aoun (@bzah), Pascal Bourgault (@aulemahal), David Huard (@huard), Juliette Lavoie (@juliettelavoie), Travis Logan (@tlogan2000), Trevor James Smith (@Zeitsperre).

New indicators

• thawing_degree_days indicator returns degree-days above a default of thresh=”0 degC”. (PR/895, GH/887).

• freezing_degree_days indicator returns degree-days below a default of thresh=”0 degC”. (PR/895, GH/887).

• Several frost-free season calculations are now available as both indices and indicators. (PR/895, GH/887):

  • frost_free_season_start

  • frost_free_season_end

  • frost_free_season_length

• growing_season_start is now offered as an indice and as an indicator to complement other growing season-based indicators (threshold calculation with op=”>=”). (PR/895, GH/887).

New features and enhancements

• Improve cell_methods checking to search the wanted method within the whole string. (PR/866, GH/863).

• New align_on='random option for xclim.core.calendar.convert_calendar, for conversions involving ‘360_day’ calendars. (PR/875, GH/841).

• dry_spell_frequency now has a parameter op: {“sum”, “max”} to choose if the threshold is compared against the accumulated or maximal precipitation, over the given window. (PR/879).

• maximum_consecutive_frost_free_days is now checking that the minimum temperature is above or equal to the threshold ( instead of only above). (PR/883, GH/881).

• The ANUCLIM virtual module has been updated to accept weekly and monthly inputs and with improved metadata. (PR/885, GH/538)

• The sdba.loess algorithm has been optimized to run faster in all cases, with an even faster special case (equal_spacing=True) when the x coordinate is equally spaced. When activated, this special case might return results different from without, up to around 0.1%. (PR/865).

• Add support for group’s window and additional dimensions in LoessDetrend. Add new RollingMeanDetrend object. (PR/865).

• Missing value algorithms now try to infer the source timestep of the input data when it is not given. (PR/885).

• On indices, bootstrap parameter documentation has been updated to explain when and why it should be used. (PR/893, GH/846).

Breaking changes

• Major changes in the YAML schema for virtual submodules, now closer to how indicators are declared dynamically, see the doc for details. (PR/849, GH/848).

• Removed xclim.generic.daily_downsampler, as it served no purpose now that xarray’s resampling works with cftime (PR/888, GH/889).

• Refactor of xclim.core.calendar.parse_offset, output types were changed to useful ones (PR/885).

• Major changes on how parameters are passed to indicators. (PR/873):

  • Their signature is now consistent : input variables (DataArrays, optional or not) are positional or keyword arguments and all other parameters are keyword only. (GH/855, GH/857)

  • Some indicators have modified signatures because we now rename variables when wrapping generic indices. This is the case for the whole cf module, for example.

  • Indicator.parameters is now a property generated from Indicator._all_parameters, as the latter includes the injected parameters. The keys of the former are instances of new xclim.core.indicator.Parameter, and not dictionaries as before.

  • New Indicator.injected_parameters to see which compute function arguments will be injected at call time.

  • See the pull request (PR/873) for all information.

• The call signature for huglin_index has been modified to reflect the correct variables used in its formula (tasmin -> tas; thresh_tasmin -> thresh). (PR/903, GH/902).

Internal changes

• Pull Request contributions now require hyperlinks to the issue and pull request pages on GitHub listed alongside changess in HISTORY.rst. (PR/860, GH/854).

• Updated the contribution guidelines to better give credit to contributors and more easily track changes. (PR/869, GH/868).

• Enabled coveralls code coverage reporting for GitHub CI. (PR/870).

• Added automated TestPyPI and PyPI-publishing workflows for GitHub CI. (PR/872).

• Changes on how indicators are constructed. (PR/873).

• Added missing algorithms tests for conversion from hourly to daily. (PR/888).

• Updated pre-commit hooks to use black v21.10.b0. (PR/896).

• Moved stack_variables, unstack_variables, construct_moving_yearly_window and unpack_moving_yearly_window from xclim.sdba.base to xclim.sdba.processing. They still are imported in xclim.sdba as before. (PR/892).

• Many improvements to the documentation. (PR/892, GH/880).

• Added regex replacement handling in setup.py to facilitate publishing contributor/contribution links on PyPI. (PR/906).

Bug fixes

• Fix a bug in bootstrapping where computation would fail when the dataset time coordinate is encoded using cftime.datetime. (PR/859).

• Fix a bug in build_indicator_module_from_yaml where bases classes (Daily, Hourly, etc) were not usable with the base field. (PR/885).

• percentile_doy alpha and beta parameters are now properly transmitted to bootstrap calls of this function. (PR/893, GH/846).

• When called with a 1D da and ND index, xclim.indices.run_length.lazy_indexing now drops the auxiliary coordinate corresponding to da’s index. This fixes a bug with ND data in xclim.indices.run_length.season. (PR/900).

• Fix name of heating degree days in French (“chauffe” -> “chauffage”). (PR/895).

• Corrected several French indicator translation description strings (bad usages of “.” in description and long_name fields). (PR/895).

• Fixed an error with the formula for huglin_index where tasmin was being used in the calculation instead of tas. (PR/903, GH/902).

v0.30.1 (2021-10-01)

Bug fixes

• Fix a bug in xclim.sdba’s map_groups where 1D input including an auxiliary coordinate would fail with an obscure error on a reducing operation.

v0.30.0 (2021-09-28)

New indicators

• climatological_mean_doy indice returns the mean and standard deviation across a climatology according to day-of-year (xarray.DataArray.groupby(“time.dayofyear”)). A moving window averaging of days can also be supplied (default:window=1).

• within_bnds_doy indice returns a boolean array indicating whether or not array’s values are within bounds for each day of the year.

• Added atmos.wet_precip_accumulation, an indicator accumulating precipitation over wet days.

• Module ICCLIM now includes PRCPTOT, which accumulates precipitation for days with precipitation above 1 mm/day.

New features and enhancements

• xclim.core.utils.nan_calc_percentiles now uses a custom algorithm instead of numpy.nanpercentiles to have more flexibility on the interpolation method. The performance is also improved.

• xclim.core.calendar.percentile_doy now uses the 8th method of Hyndman & Fan for linear interpolation (alpha = beta = 1/3). Previously, the function used Numpy’s percentile, which corresponds to the 7th method. This change is motivated by the fact that the 8th is recommended by Hyndman & Fay and it ensures consistency with other climate indices packages (climdex, icclim). Using alpha = beta = 1 restores the previous behaviour.

• xclim.core.utils._cal_perc is now only a proxy for xc.core.utils.nan_calc_percentiles with some axis moves.

• xclim now implements many data quality assurance flags (xclim.core.dataflags) for temperature and precipitation based on ICCLIM documentation guidelines. These checks include the following:

  • Temperature (variables: tas, tasmin, tasmax): tasmax_below_tasmin, tas_exceeds_tasmax, tas_below_tasmin, temperature_extremely_low (thresh=”-90 degC”), temperature_extremely_high (thresh=”60 degC”).

  • Precipitation-specific (variables: pr, prsn, ): negative_accumulation_values, very_large_precipitation_events (thresh=”300 mm d-1”).

  • Wind-specific (variables: sfcWind, wsgsmax/sfcWindMax): wind_values_outside_of_bounds

  • Generic: outside_n_standard_deviations_of_climatology, values_repeating_for_n_or_more_days, values_op_thresh_repeating_for_n_or_more_days, percentage_values_outside_of_bounds.

  These quality-assurance checks are selected according to CF-standard variable names, and can be triggered via xclim.core.dataflags.data_flags(xarray.DataArray, xarray.Dataset). These checks are separate from the Indicator-defined datachecks and must be launched manually. They’ll return an array of data_flags as boolean variables. If called with raise_flags=True, will raise an Exception with comments for each quality control check raised.

• A convenience function (xclim.core.dataflags.ecad_compliant) is also offered as a method for asserting that data adheres to all relevant ECAD/ICCLIM checks. For more information on usage, consult the docstring/documentation.

• A new utility “dataflags” is also available for performing fast quality control checks from the command-line (xclim dataflags –help). See the CLI documentation page for usage examples.

• Added missing typed call signatures, expected returns and docstrings for many xclim.core.calendar functions.

Breaking changes

• All “ANUCLIM” indices and indicators have lost their src_timestep argument. Most of them were not using it and now every function infers the frequency from the data directly. This may add stricter constraints on the time coordinate, the same as for xarray.infer_freq.

• Many functions found within xclim.core.cfchecks (generate_cfcheck and check_valid_*) have been removed as existing indicator CF-standard checks and data checks rendered them redundant/obsolete.

Bug fixes

• Fixes in sdba for (1) inputs with dimensions without coordinates, for (2) sdba.detrending.MeanDetrend and for (3) DetrendedQuantileMapping when used with dask’s distributed scheduler.

• Replaced instances of ‘◦’ (“White bullet”) with ‘°’ (“Degree Sign”) in icclim.yaml as it was causing issues for non-UTF8 environments.

• Addressed an edge case where test_sdba::test_standardize randomness could generate values that surpass the test error tolerance.

• Added a missing .txt file to the MANIFEST of the source distributable in order to be able to run all tests.

• xc.core.units.rate2amount is now exact when the sampling frequency is monthly, seasonal or yearly. Earlier, monthly and yearly data were computed using constant month and year length. End-of-period frequencies are also correctly understood (ex: “M” vs “MS”).

• In the potential_evapotranspiration indice, add abbreviated method names to docstring.

• Fixed an issue that prevented using the default group arg in adjustment objects.

• Fix bug in missing_wmo, where a period would be considered valid if all months met WMO criteria, but complete months in a year were missing. Now if any month does not meet criteria or is absent, the period will be considered missing.

• Fix bootstrapping with dask arrays. Dask does not support using loc with multiple indexes to set new values so a workaround was necessary.

• Fix bootstrapping when the bootstrapped year must be converted to a 366_day calendar.

• Virtual modules and translations now use ‘UTF-8’ by default when reading yaml or json file, instead of a machine-dependent encoding.

Internal Changes

• xclim code quality checks now use the newest black (v21.8-beta). Checks launched via tox and pre-commit now run formatting modifications over Jupyter notebooks found under docs.

v0.29.0 (2021-08-30)

Announcements

• It was found that the ExtremeValues adjustment algorithm was not as accurate and stable as first thought. It is now hidden from xclim.sdba but can still be accessed via xclim.sdba.adjustment, with a warning. Work on improving the algorithm is ongoing, and a better implementation will be in a future version.

• It was found that the add_dims argument of sdba.Grouper had some caveats throughout sdba. This argument is to be used with care before a careful analysis and more testing is done within xclim.

Breaking changes

• xclim has switched back to updating the history attribute (instead of xclim_history). This impacts all indicators, most ensemble functions, percentile_doy and sdba.processing (see below).

• Refactor of sdba.processing. Now all functions take one or more DataArrays as input, plus some parameters. And output one or more dataarrays (not Datasets). Units and metadata is handled. This impacts sdba.processing.adapt_freq especially.

• Add unit handling in sdba. Most parameters involving quantities are now expecting strings (and not numbers). Adjustment objects will ensure ref, hist and sim all have the same units (taking ref as reference).

• The Adjustment` classes of xclim.sdba have been refactored into 2 categories:

  • TrainAdjust objects (most of the algorithms), which are created and trained in the same call: obj = Adj.train(ref, hist, **kwargs). The .adjust step stays the same.

  • Adjust objects (only NpdfTransform), which are never initialized. Their adjust class method performs all the work in one call.

• snowfall_approximation used a “<” condition instead of “<=” to determine the snow fraction based on the freezing point temperature. The new version sticks to the convention used in the Canadian Land Surface Scheme (CLASS).

• Removed the “gis”, “docs”, “test” and “setup”`extra dependencies from ``setup.py`. The dev recipe now includes all tools needed for xclim’s development.

New features and enhancements

• snowfall_approximation has gained support for new estimation methods used in CLASS: ‘brown’ and ‘auer’.

• A ValidationError will be raised if temperature units are given as ‘deg C’, which is misinterpreted by pint.

• Functions computing run lengths (sequences of consecutive “True” values) now take the index argument. Possible values are first and last, indicating which item in the run should be used to index the run length. The default is set to “first”, preserving the current behavior.

• New sdba_encode_cf option to workaround a cftime/xarray performance issue when using dask.

New indicators

• effective_growing_degree_days indice returns growing degree days using dynamic start and end dates for the growing season (based on Bootsma et al. (2005)). This has also been wrapped as an indicator.

• qian_weighted_mean_average (based on Qian et al. (2010)) is offered as an alternate method for determining the start date using a weighted 5-day average (method="qian"). Can also be used directly as an indice.

• cold_and_dry_days indicator returns the number of days where the mean daily temperature is below the 25th percentile and the mean daily precipitation is below the 25th percentile over period. Added as CD indicator to ICCLIM module.

• warm_and_dry_days indicator returns the number of days where the mean daily temperature is above the 75th percentile and the mean daily precipitation is below the 25th percentile over period. Added as WD indicator to ICCLIM module.

• warm_and_wet_days indicator returns the number of days where the mean daily temperature is above the 75th percentile and the mean daily precipitation is above the 75th percentile over period. Added as WW indicator to ICCLIM module.

• cold_and_wet_days indicator returns the number of days where the mean daily temperature is below the 25th percentile and the mean daily precipitation is above the 75th percentile over period. Added as CW indicator to ICCLIM module.

• calm_days indicator returns the number of days where surface wind speed is below threshold.

• windy_days indicator returns the number of days where surface wind speed is above threshold.

Bug fixes

• Various bug fixes in bootstrapping:

  • in percentile_bootstrap decorator, fix the popping of bootstrap argument to propagate in to the function call.

  • in bootstrap_func, fix some issues with the resampling frequency which was not working when anchored.

• Made argument thresh of sdba.LOCI required, as not giving it raised an error. Made defaults explicit in the adjustments docstrings.

• Fixes in sdba.processing.adapt_freq and sdba.nbutils.vecquantiles when handling all-nan slices.

• Dimensions in a grouper’s add_dims are now taken into consideration in function wrapped with map_blocks/groups. This feature is still not fully tested throughout sdba though, so use with caution.

• Better dtype preservation throughout sdba.

• “constant” extrapolation in the quantile mappings’ adjustment is now padding values just above and under the target’s max and min, instead of ±np.inf.

• Fixes in sdba.LOCI for the case where a grouping with additional dimensions is used.

Internal Changes

• The behaviour of xclim.testing._utils.getfile was adjusted to launch file download requests for web-hosted md5 files for every call to compare against local test data. This was done to validate that locally-stored test data is identical to test data available online, without resorting to git-based actions. This approach may eventually be revised/optimized in the future.

v0.28.1 (2021-07-29)

Announcements

• The xclim binary package available on conda-forge will no longer supply clisops by default. Installation of clisops must be performed explicitly to preserve subsetting and bias correction capabilities.

New indicators

• snow_depth indicator returns the mean snow depth over period. Added as SD to ICCLIM module.

Internal Changes

• Minor modifications to many function call signatures (type hinting) and docstrings (numpy docstring compliance).

v0.28.0 (2021-07-07)

New features and enhancements

• Automatic load of translations on import and possibility to pass translations for virtual modules.

• New xclim.testing.list_datasets function listing all available test datasets in repo xclim-testdata.

• spatial_analogs accepts multi-indexes as the dist_dim parameter and will work with candidates and target arrays of different lengths.

• humidex can be computed using relative humidity instead of dewpoint temperature.

• New sdba.construct_moving_yearly_window and sdba.unpack_moving_yearly_window for moving window adjustments.

• New sdba.adjustment.NpdfTransform which is an adaptation of Alex Cannon’s version of Pitié’s N-dimensional probability density function transform. Uses new sdba.utils.rand_rot_matrix. Experimental, subject to changes.

• New sdba.processing.standardize, .unstandardize and .reordering. All of them, tools needed to replicate Cannon’s MBCn algorithm.

• New sdba.processing.escore, backed by sdba.nbutils._escore to evaluate the performance of the N pdf transform.

• New function xclim.indices.clausius_clapeyron_scaled_precipitation can be used to scale precipitation according to changes in mean temperature.

• Percentile based indices gained a bootstrap argument that applies a bootstrapping algorithm to reduce biases on exceedance frequencies computed over in base and out of base periods. Experimental, subject to changes.

• Added a .zenodo.json file for collecting and maintaining author order and tracking ORCIDs.

Bug fixes

• Various bug fixes in sdba :

  • in QDM.adjust, fix bug occurring with coords of ‘object’ dtype and interp='nearest'.

  • in nbutils.quantiles, fix dtype bug when using float32 data.

  • raise a proper error when ref and hist have a different calendar for map_blocks-backed adjustments.

Breaking changes

• spatial_analogs does not support sequence of dist_dim anymore. Users are responsible for stacking dimensions prior to calling spatial_analogs.

New indicators

• biologically_effective_degree_days (with method="gladstones") indice computes degree-days between two specific dates, with a capped daily max value as well as latitude and temperature range swing as modifying coefficients (based on Gladstones, J. (1992)). This has also been wrapped as an indicator.

• An alternative implementation of biologically_effective_degree_days (with method="icclim", based on ICCLIM formula) ignores latitude and temperature range swing modifiers and uses an alternate end_date. Wrapped and available as an ICCLIM indicator.

• cool_night_index indice returns the mean minimum temperature in September (lat >= 0 deg N) or March (lat < 0 deg N), based on Tonietto & Carbonneau, 2004 (10.1016/j.agrformet.2003.06.001). Also available as an indicator (see indices Notes section on indicator usage recommendations).

• latitude_temperature_index indice computes LTI values based on mean temperature of warmest month and a parameterizable latitude coefficient (default: lat_factor=75) based on Jackson & Cherry, 1988, and Kenny & Shao, 1992 (10.1080/00221589.1992.11516243). This has also been wrapped as an indicator.

• huglin_index indice computes Huglin Heliothermal Index (HI) values based on growing degrees and a latitude-influenced coefficient for day-length (based on Huglin. (1978)). The indice supports several methods of estimating the latitude coefficient:

  • method="smoothed": Marks latitudes between -40 N and 40 N with k=1, and linearly increases to k=1.06 at |lat|==50.

  • method="icclim": Uses a stepwise function based on the the original method as presented by Huglin (1978). Identical to the ICCLIM implementation.

  • method="jones": Uses a more robust calculation for calculating day-lengths, based on Hall & Jones (2010). This method is now also available for biologically_effective_degree_days.

• The generic indice day_length, used for calculating approximate daily day-length in hours per day or, given start_date and end_date, the total aggregated day-hours over period. Uses axial tilt, start and end dates, calendar, and approximate date of northern hemisphere summer solstice, based on Hall & Jones (2010).

Internal Changes

• aggregate_between_dates (introduced in v0.27.0) now accepts DayOfYear-like strings for supplying start and end dates (e.g. start="02-01", end="10-31").

• The indicator call sequence now considers “variable” the inputs annotated so. Dropped the nvar attribute.

• Default cfcheck is now to check metadata according to the variable name, using CMIP6 names in xclim/data/variable.yml.

• Indicator.missing defaults to “skip” if freq is absent from the list of parameters.

• Minor modifications to the GitHub Pull Requests template.

• Simplification of some yaml elements for virtual modules.

• Allow injecting freq without the missing checks failing.

v0.27.0 (2021-05-28)

New features and enhancements

• Rewrite of nearly all adjustment methods in sdba, with use of xr.map_blocks to improve scalability with dask. Rewrite of some parts of the algorithms with numba-accelerated code.

• “GFWED” specifics for fire weather computation implemented back into the FWI module. Outputs are within 3% of GFWED data.

• Addition of the run_length_ufunc option to control which run length algorithm gets run. Defaults stay the same (automatic switch dependent of the input array : the 1D version is used with non-dask arrays with less than 9000 points per slice).

• Indicator modules built from YAML can now use custom indices. A mapping or module of them can be given to build_indicator_module_from_yaml with the indices keyword.

• Virtual submodules now include an iter_indicators function to iterate over the pairs of names and indicator objects in that module.

• The indicator string formatter now accepts a “r” modifier which passes the raw strings instead of the adjective version.

• Addition of the sdba_extra_output option to adds extra diagnostic variables to the outputs of Adjustment objects. Implementation of sim_q in QuantileDeltaMapping and nclusters in ExtremeValues.

Breaking changes

• The tropical_nights indice is being deprecated in favour of tn_days_above with thresh="20 degC". The indicator remains valid, now wrapping this new indice.

• Results of sdba.Grouper.apply for Grouper without a group (ex: Grouper('time')) will contain a group singleton dimension.

• The daily_freezethaw_cycles indice is being deprecated in favour of multiday_temperature_swing with temp thresholds at 0 degC and window=1, op="sum". The indicator remains valid, now wrapping this new indice.

• CMIP6 variable names have been adopted whenever possible in xclim. Changes are:

  • swe is now snw (snw is the snow amount [kg / m²] and swe the liquid water equivalent thickness [m])

  • rh is now hurs

  • dtas is now tdps

  • ws (in FWI) is now sfcWind

  • sic is now siconc

  • area (of sea ice indicators) is now areacello

  • Indicators RH and RH_FROMDEWPOINT have be renamed to HURS and HURS_FROMDEWPOINT. These are changes in the _identifiers_, the python names (relative_humidity[...]) are unchanged.

New indicators

• atmos.corn_heat_units computes the daily temperature-based index for corn growth.

• New indices and indicators for tx_days_below, tg_days_above, tg_days_below, and tn_days_above.

• atmos.humidex returns the Canadian humidex, an indicator of perceived temperature account for relative humidity.

• multiday_temperature_swing indice for returning general statistics based on spells of doubly-thresholded temperatures (Tmin < T1, Tmax > T2).

• New indicators atmos.freezethaw_frequency, atmos.freezethaw_spell_mean_length, atmos.freezethaw_spell_max_length for statistics of Tmin < 0 degC and Tmax > 0 deg C days now available (wrapped from multiday_temperature_swing).

• atmos.wind_chill_index computes the daily wind chill index. The default is similar to what Environment and Climate Change Canada does, options are tunable to get the version of the National Weather Service.

Internal Changes

• run_length.rle_statistics now accepts a window argument.

• Common arguments to the op parameter now have better adjective and noun formatting.

• Added and adjusted typing in call signatures and docstrings, with grammar fixes, for many xclim.indices operations.

• Added internal function aggregate_between_dates for array aggregation operations using xarray datetime arrays with start and end DayOfYear values.

v0.26.1 (2021-05-04)

• Bug fix release adding ExtremeValues to publicly exposed bias-adjustment methods.

v0.26.0 (2021-04-30)

Announcements

• xclim no longer supports Python3.6. Code conventions and new features from Python3.7 (PEP 537 Features) are now accepted.

New features and enhancements

• core.calendar.doy_to_days_since and days_since_to_doy to allow meaningful statistics on doy data.

• New bias second-order adjustment method “ExtremeValues”, intended for re-adjusting extreme precipitation values.

• Virtual indicators modules can now be built from YAML files.

• Indicators can now be built from dictionaries.

• New generic indices, implementation of clix-meta’s index functions.

• On-the-fly generation of climate and forecasting convention (CF) checks with xc.core.cfchecks.generate_cfcheck, for a few known variables only.

• New xc.indices.run_length.rle_statistics for min, max, mean, std (etc) statistics on run lengths.

• New virtual submodule cf, with CF standard indices defined in clix-meta.

• Indices returning day-of-year data add two new attributes to the output: is_dayofyear (=1) and calendar.

Breaking changes

• xclim now requires xarray>=0.17.

• Virtual submodules icclim and anuclim are not available at the top level anymore (only through xclim.indicators).

• Virtual submodules icclim and anuclim now provide Indicators and not indices.

• Spatial analog methods “KLDIV” and “Nearest Neighbor” now require scipy>=1.6.0.

Bug fixes

• from_string object creation in sdba has been removed. Now replaced with use of a new dependency, jsonpickle.

Internal Changes

• pre-commit linting checks now run formatting hook black==21.4b2.

• Code cleaning (more accurate call signatures, more use of https links, docstring updates, and typo fixes).

v0.25.0 (2021-03-31)

Announcements

• Deprecation: Release 0.25.0 of xclim will be the last version to explicitly support Python3.6 and xarray<0.17.0.

New indicators

• land.winter_storm computes days with snow accumulation over threshold.

• land.blowing_snow computes days with both snow accumulation over last days and high wind speeds.

• land.snow_melt_we_max computes the maximum snow melt over n days, and land.melt_and_precip_max the maximum combined snow melt and precipitation.

• snd_max_doy returns the day of the year where snow depth reaches its maximum value.

• atmos.high_precip_low_temp returns days with freezing rain conditions (low temperature and precipitations).

• land.snow_cover_duration computes the number of days snow depth exceeds some minimal threshold.

• land.continuous_snow_cover_start and land.continuous_snow_cover_end identify the day of the year when snow depth crosses a threshold for a given period of time.

• days_with_snow, counts days with snow between low and high thresholds, e.g. days with high amount of snow (indice and indicator available).

• fire_season, creates a fire season mask from temperature and, optionally, snow depth time-series.

New features and enhancements

• generic.count_domain counts values within low and high thresholds.

• run_length.season returns a dataset storing the start, end and length of a season.

• Fire Weather indices now support dask-backed data.

• Objects from the xclim.sdba submodule can be created from their string repr or from the dataset they created.

• Fire Weather Index submodule replicates the R code of cffdrs, including fire season determination and overwintering of the drought_code.

• New run_bounds and keep_longest_run utilities in xclim.indices.run_length.

• New bias-adjustment method: PrincipalComponent (based on Hnilica et al. 2017 https://doi.org/10.1002/joc.4890).

Internal changes

• Small changes in the output of indices.run_length.rle.

v0.24.0 (2021-03-01)

New indicators

• days_over_precip_thresh, fraction_over_precip_thresh, liquid_precip_ratio, warm_spell_duration_index, all from eponymous indices.

• maximum_consecutive_warm_days from indice maximum_consecutive_tx_days.

Breaking changes

• Numerous changes to xclim.core.calendar.percentile_doy:

  • per now accepts a sequence as well as a scalar and as such the output has a percentiles axis.

  • per argument is now expected to between 0-100 (not 0-1).

  • input data must have a daily (or coarser) time frequency.

• Change in unit handling paradigm for indices, which as a result will lead to some indices returning values with different units. Note that related Indicator objects remain unchanged and will return units consistent with CF Convention. If you are concerned with code stability, please use Indicator objects. The change was necessary to resolve inconsistencies with xarray’s keep_attrs=True context.

  • Indice functions now return output units that preserve consistency with input units. That is, feeding inputs in Celsius will yield outputs in Celsius instead of casting to Kelvin. In all cases the dimensionality is preserved.

  • Indice functions now accept non-daily data, but daily frequency is assumed by default if the frequency cannot be inferred.

• Removed the explicitly-installed netCDF4 python library from the base installation, as this is never explicitly used (now only installed in the docs recipe for sdba documented example).

• Removed xclim.core.checks, which was deprecated since v0.18.

New features and enhancements

• Indicator now have docstrings generated from their metadata.

• Units and fixed choices set are parsed from indice docstrings into Indicator.parameters.

• Units of indices using the declare_units decorator are stored in indice.in_units and indice.out_units.

• Changes to Indicator.format and Indicator.json to ensure the resulting json really is serializable.

Internal changes

• Leave missing_options undefined in land.fit indicator to allow control via set_options.

• Modified xclim.core.calendar.percentile_doy to improve performance.

• New xclim.core.calendar.compare_offsets for comparing offset strings.

• New xclim.indices.generic.get_op to retrieve a function from a string representation of that operator.

• The CI pipeline has been migrated from Travis CI to GitHub Actions. All stages are still built using tox.

• Indice functions must always set the units (the declare_units decorator does no check anymore).

• New xclim.core.units.rate2amout to convert rates like precipitation to amounts.

• xclim.core.units.pint2cfunits now removes ‘ * ‘ symbols and changes Δ° to delta_deg.

• New xclim.core.units.to_agg_units and xclim.core.units.infer_sampling_units for unit handling involving aggregation operations along the time dimension.

• Added an indicators API page to the docs and links to there from the Climate Indicators page.

Bug fixes

• The unit handling change resolved a bug that prevented the use of xr.set_options(keep_attrs=True) with indices.

v0.23.0 (2021-01-22)

Breaking changes

• Renamed indicator atmos.degree_days_depassment_date to atmos.degree_days_exceedance_date.

• In degree_days_exceedance_date : renamed argument start_date to after_date.

• Added cfchecks for Pr+Tas-based indicators.

• Refactored test suite to now be available as part of the standard library installation (xclim.testing.tests).

• Running pytest with xdoctest now requires the rootdir to point at tests location (pytest –rootdir xclim/testing/tests/ –xdoctest xclim).

• Development checks now require working jupyter notebooks (assessed via the pytest –nbval command).

New indicators

• rain_approximation and snowfall_approximation for computing prlp and prsn from pr and tas (or tasmin or tasmax) according to some threshold and method.

• solid_precip_accumulation and liquid_precip_accumulation now accept a thresh parameter to control the binary snow/rain temperature threshold.

• first_snowfall and last_snowfall to compute the date of first/last snowfall exceeding a threshold in a period.

New features and enhancements

• New kind entry in the parameters property of indicators, differentiating between [optional] variables and parameters.

• The git pre-commit hooks (pre-commit run –all) now clean the jupyter notebooks with nbstripout call.

Bug fixes

• Fixed a bug in indices.run_length.lazy_indexing that occurred with 1D coords and 0D indexes when using the dask backend.

• Fixed a bug with default frequency handling affecting fit indicator.

• Set missing method to ‘skip’ for freq_analysis indicator.

• Fixed a bug in ensembles._ens_align_datasets that occurred when inputs are .nc filepaths but files lack a time dimension.

Internal changes

• core.cfchecks.check_valid now accepts a sequence of strings as its expected argument.

• Clean up in the tests to speed up testing. Addition of a marker to include “slow” tests when desired (-m slow).

• Fixes in the tests to support sklearn>=0.24, clisops>=0.5 and build xarray@master against python 3.7.

• Moved the testing suite to within xclim and simplified tox to manage its own tempdir.

• Indicator class now has a default_freq method.

v0.22.0 (2020-12-07)

Breaking changes

• Statistical functions (frequency_analysis, fa, fit, parametric_quantile) are now solely accessible via indices.stats.

New indicators

• atmos.degree_days_depassment_date, the day of year when the degree days sum exceeds a threshold.

New features and enhancements

• Added unique titles to atmos calculations employing wrapped_partials.

• xclim.core.calendar.convert_calendar now accepts a missing argument.

• Added xclim.core.calendar.date_range and xclim.core.calendar.date_range_like wrapping pandas’ date_range and xarray’s cftime_range.

• xclim.core.calendar.get_calendar now accepts many different types of data, including datetime object directly.

• New module xclim.analog and method xclim.analog.spatial_analogs to compute spatial analogs.

• Indicators can now accept dataset in their new ds call argument. Variable arguments (that use the DataArray annotation) can now be given with strings that correspond to variable names in the dataset, and default to their own name.

• Clarification to frequency_analysis notebook.

• Now officially supporting PEP596 (Python3.9).

• New methods xclim.ensembles.change_significance and xclim.ensembles.knutti_sedlacek to qualify climate change agreement among members of an ensemble.

Bug fixes

• Fixed bug that prevented the use of xclim.core.missing.MissingBase and subclasses with an indexer and a cftime datetime coordinate.

• Fixed issues with metadata handling in statistical indices.

• Various small fixes to the documentation (re-establishment of some internally and externally linked documents).

Internal changes

• Passing align_on to xclim.core.calendar.convert_calendar without using ‘360_day’ calendars will not raise a warning anymore.

• Added formatting utilities for metadata attributes (update_cell_methods, prefix_attrs and unprefix_attrs).

• xclim/ensembles.py moved to xclim/ensembles/*.py, splitting stats/creation, reduction and robustness methods.

• With the help of the mypy library, added several typing fixes to better identify inputs/outputs, and reduce object type mutations.

• Fixed some doctests in ensembles and set_options.

• clisops v0.4.0+ is now an optional requirements for non-Windows builds.

• New xclim.core.units.str2pint method to convert quantity strings to quantity objects. Main improvement is to make “3 degC days” a valid string that converts to “3 K days”.

v0.21.0 (2020-10-23)

Breaking changes

• Statistical functions (frequency_analysis, fa, fit, parametric_quantile) moved from indices.generic to indices.stats to make them more visible.

New indicators

New features and enhancements

• New xclim.testing.open_dataset method to read data from the remote testdata repo.

• Added a notebook, ensembles-advanced.ipynb, to the documentation detailing ensemble reduction techniques and showing how to make use of built-in figure-generating commands.

• Added a notebook, frequency_analysis.ipynb, with examples showcasing frequency analysis capabilities.

Bug fixes

• Fixed a bug in the attributes of frost_season_length.

• indices.run_length methods using dates now respect the array’s calendar.

• Worked around an xarray bug in sdba.QuantileDeltaMapping when multidimensional arrays are used with linear or cubic interpolation.

Internal changes

v0.20.0 (2020-09-18)

Breaking changes

• xclim.subset has been deprecated and now relies on clisops to perform specialized spatio-temporal subsetting. Install with pip install xclim[gis] in order to retain the same functionality.

• The python library pandoc is no longer listed as a docs build requirement. Documentation still requires a current version of pandoc binaries installed at system-level.

• ANUCLIM indices have seen their input_freq parameter renamed to src_timestep for clarity.

• A clean-up and harmonization of the indicators metadata has changed some of the indicator identifiers, long_names, abstracts and titles. xclim.atmos.drought_code and fire_weather_indexes now have identifiers “dc” and “fwi” (lowercase version of the previous identifiers).

• xc.indices.run_length.run_length_with_dates becomes xc.indices.run_length.season_length. Its argument date is now optional and the default changes from “07-01” to None.

• xc.indices.consecutive_frost_days becomes xc.indices.maximum_consecutive_frost_days.

• Changed the history indicator output attribute to xclim_history in order to respect CF conventions.

New indicators

• atmos.max_pr_intensity acting on hourly data.

• atmos.wind_vector_from_speed, also the wind_speed_from_vector now also returns the “wind from direction”.

• Richards-Baker flow flashiness indicator (xclim.land.rb_flashiness_index).

• atmos.max_daily_temperature_range.

• atmos.cold_spell_frequency.

• atmos.tg_min and atmos.tg_max.

• atmos.frost_season_length, atmos.first_day_above. Also, atmos.consecutive_frost_days now takes a thresh argument (default : 0 degC).

New features and enhancements

• sdba.loess submodule implementing LOESS smoothing tools used in sdba.detrending.LoessDetrend.

• xclim now depends on clisops for subsetting, offloading several heavy GIS dependencies. This improves maintainability and reduces the size of a “vanilla” xclim installation considerably.

• New generic.parametric_quantile function taking parameters estimated by generic.fit as an input.

• Add support for using probability weighted moments method in generic.fit function. Requires the lmoments3 package, which is not included in dependencies because it is unmaintained. Install manually if needed.

• Implemented _fit_start utility function providing initial conditions for statistical distribution parameters estimation, reducing the likelihood of poor fits.

• Added support for indicators based on hourly (1H) inputs, and a first hourly indicator called max_pr_intensity returning hourly precipitation intensity.

• Indicator instances can be retrieved through their class with the get_instance() class method. This allows the use of xclim.core.indicator.registry as an instance registry.

• Indicators now have a realm attribute. It must be given when creating indicators outside xclim.

• Better docstring parsing for indicators: parameters description, annotation and default value are accessible in the json output and Indicator.parameters.

• New command line interface xclim for simple indicator computing tasks.

• New sdba.processing.jitter_over_thresh for variables with a upper bound.

• Added op parameter to xclim.indices.daily_temperature_range to allow resample reduce operations other than mean

• core.formatting.AttrFormatter (and thus, locale dictionaries) can now use glob-like pattern for matching values to translate.

Bug fixes

The ICCLIM module was identified as icclim in the documentation but the module available under ICCLIM. Now icclim == ICCLIM and ICCLIM will be deprecated in a future release.

Internal changes

• xclim.subset now attempts to load and expose the functions of clisops.core.subset. This is an API workaround preserving backwards compatibility.

• Code styling now conforms to the latest release of black (v0.20.8).

• New IndicatorRegistrar class that takes care of adding indicator classes and instances to the appropriate registries. Indicator now inherits from it.

v0.19.0 (2020-08-18)

Breaking changes

• Refactoring of the Indicator class. The cfprobe method has been renamed to cfcheck and the validate method has been renamed to datacheck. More importantly, instantiating Indicator creates a new subclass on the fly and stores it in a registry, allowing users to subclass existing indicators easily. The algorithm for missing values is identified by its registered name, e.g. “any”, “pct”, etc, along with its missing_options.

• xclim now requires xarray >= 0.16, ensuring that xclim.sdba is fully functional.

• The dev requirements now include xdoctest – a rewrite of the standard library module, doctest.

• xclim.core.locales.get_local_attrs now uses the indicator’s class name instead of the indicator itself and no longer accepts the fill_missing keyword. Behaviour is now the same as passing False.

• Indicator.cf_attrs is now a list of dictionaries. Indicator.json puts all the metadata attributes in the key “outputs” (a list of dicts). All variable metadata (names in Indicator._cf_names) might be strings or lists of strings when accessed as object attributes.

• Passing doctests are now strictly enforced as a build requirement in the Travis CI testing ensemble.

New features and enhancements

• New ensembles.kkz_reduce_ensemble method to select subsets of an ensemble based on the KKZ algorithm.

• Create new Indicator Daily, Daily2D subclasses for indicators using daily input data.

• The Indicator class now supports outputting multiple indices for the same inputs.

• xclim.core.units.declare_units now works with indices outputting multiple DataArrays.

• Doctests now make use of the xdoctest_namespace in order to more easily access modules and testdata.

Bug fixes

• Fix generic.fit dimension ordering. This caused errors when “time” was not the first dimension in a DataArray.

Internal changes

• datachecks.check_daily now uses xr.infer_freq.

• Indicator subclasses Tas, Tasmin, Tasmax, Pr and Streamflow now inherit from Daily.

• Indicator subclasses TasminTasmax and PrTas now inherit from Daily2D.

• Docstring style now enforced using the pydocstyle with numpy docstring conventions.

• Doctests are now performed for all docstring Examples using xdoctest. Failing examples must be explicitly skipped otherwise build will now fail.

• Indicator methods update_attrs and format are now classmethods, attrs to update must be passed.

• Indicators definitions without an accompanying translation (presently French) will cause build failures.

• Major refactoring of the internal machinery of Indicator to support multiple outputs.

v0.18.0 (2020-06-26)

• Optimization options for xclim.sdba : different grouping for the normalization steps of DQM and save training or fitting datasets to temporary files.

• xclim.sdba.detrending objects can now act on groups.

• Replaced dask[complete] with dask[array] in basic installation and added distributed to docs build dependencies.

• xclim.core.locales now supported in Windows build environments.

• ensembles.ensemble_percentiles modified to compute along a percentiles dimension by default, instead of creating different variables.

• Added indicator first_day_below and run length helper first_run_after_date.

• Added ANUCLIM model climate indices mappings.

• Renamed areacella to areacello in sea ice tests.

• Sea ice extent and area outputs now have units of m2 to comply with CF-Convention.

• Split checks.py into cfchecks.py, datachecks.py and missing.py. This change will only affect users creating custom indices using utilities previously located in checks.py.

• Changed signature of daily_freeze_thaw_cycles, daily_temperature_range, daily_temperature_range_variability and extreme_temperature_range to take (tasmin, tasmax) instead of (tasmax, tasmin) and match signature of other similar multivariate indices.

• Added FromContext subclass of MissingBase to have a uniform API for missing value operations.

• Remove logging commands that captured all xclim warnings. Remove deprecated xr.set_options calls.

v0.17.0 (2020-05-15)

• Added support for operations on dimensionless variables (units = ‘1’).

• Moved xclim.locales to xclim.core.locales in a batch of internal changes aimed to removed most potential cyclic imports cases.

• Missing checks and input validation refactored with addition of custom missing class registration (xclim.core.checks.register_missing_method) and simple validation method decorator (xclim.core.checks.check).

• New xclim.set_options context to control the missing checks, input validation and locales.

• New xclim.sdba module for statistical downscaling and bias-adjustment of climate data.

• Added convert_calendar and interp_calendar to help in the conversion between calendars.

• Added at_least_n_valid function, identifying null calculations based on minimum threshold.

• Added support for freq=None in missing calculations.

• Fixed outdated code examples in the docs and docstrings.

• Doctests are now run as part of the test suite.

v0.16.0 (2020-04-23)

• Added vectorize flag to subset_shape and create_mask_vectorize function based on shapely.vectorize as default backend for mask creation.

• Removed start_yr and end_yr flags from subsetting functions.

• Add multi gridpoints support in subset.subset_gridpoint.

• Better wrapped_partial for more meaningful inspection.

• Add indices for relative humidity, specific humidity and saturation vapor pressure with a few choices of method.

• Allow lazy units conversion.

• CRS definitions of projected DataSets are now written to file according to Climate and Forecast-convention standards.

• Add utilities to merge attributes and update history in xclim.core.formatting.

• Ensembles : Allow alignment of datasets with same frequency but different offsets.

• Bug fixes in run_length for run-with-dates methods when the date is not found in the run.

• Remove deepcopy from subset.subset_shape to improve memory usage.

• Add missing_wmo function, identifying null calculations based on criteria from WMO.

• Add missing_pct function, identifying null calculations based on percentage of missing values.

v0.15.x (2020-03-12)

• Improvement in FWI: Vectorization of DC, DMC and FFMC with numba and small code refactoring for better maintainability.

• Added example notebook for creating a catalog of selected indices

• Added growing_season_end, last_spring_frost, dry_days, hot_spell_frequency, hot_spell_max_length, and maximum_consecutive_frost_free_days indices.

• Dropped use of fiona.crs class in lieu of the newer pyproj CRS handler for subset_shape operations.

• Complete internal reorganization of xclim.

• Internationalization of xclim : add locales submodule for localized metadata.

• Add feature to retrieve coordinate values instead of index in run_length.first_run. Add run_length.last_run.

• Fix bug in subset_gridpoint to work on lat/lon coords of any dimension when they are not a dimension of the data.

v0.14.x (2020-02-21)

• Refactoring of the documentation.

• Added support for pint 0.10

• Add atmos.heat_wave_total_length (fixing a namespace issue)

• Fixes in utils.percentile_doy and indices.winter_rain_ratio for multidimensional datasets.

• Rewrote the subset.subset_shape function to allow for dask.delayed (lazy) computation.

• Added utility functions to compute time_bnds when resampling data encoded with CFTimeIndex (non-standard calendars).

• Fix in subset.subset_gridpoint for dask array coordinates.

• Modified subset_shape to support subsetting with GeoPandas datatypes directly.

• Fix in subset.wrap_lons_and_split_at_greenwich to preserve multi-region dataframes.

• Improve the memory use of indices.growing_season_length.

• Better handling of data with atypically named lat and lon dimensions.

• Added six Fire Weather indices.

v0.13.x (2020-01-10)

• Documentation improvements: list of indicators, RTD theme, notebook example.

• Added sea_ice_extent and sea_ice_area indicators.

• Reverted #311, removing the _rolling util function. Added optimal keywords to rolling() calls.

• Fixed ensembles.create_ensemble errors for builds against xarray master branch.

• Reformatted code to make better use of Python3.6 conventions (f-strings and object signatures).

• Fixed randomly failing tests of checks.missing_any.

• Improvement of ensemble.ensemble_percentile and ensemble.create_ensemble.

v0.12.x-beta (2019-11-18)

• Added a distance function computing the geodesic distance to a point.

• Added a tolerance argument to subset_gridpoint raising an error if distance to closest point is larger than tolerance.

• Created land module for standardized access to streamflow indices.

• Enhancement to utils.Indicator to have more dynamic attributes using callables.

• Added indices heat_wave_total_length and tas / tg to average tasmin and tasmax into tas.

• Fixed a bug with typed call signatures that caused downstream failures on library import.

• Added a _rolling util function to fix memory issues on large dask datasets.

• Added the subset_shape function to subset utilities for clipping region-masked datasets via polygons.

• Fixed a bug where certain dependencies caused ReadTheDocs builds to fail.

• Added many statically typed function signatures for better function documentation.

• Improved DeprecationWarnings and UserWarnings ensemble for xclim subsetting functions.

• Dropped support for Python3.5.

v0.11.x-beta (2019-10-17)

• Added type hinting to call signatures of many functions for more explicit type-checking.

• Added Kmeans clustering ensemble reduction algorithms.

• Added utilities for converting between wind velocity (sfcWind) and wind components (uas, vas) arrays.

• Added type hinting to call signatures of many functions for more explicit type-checking.

• Now supporting explicit builds for Windows OS via Travis CI.

• Fix failing test with Python 3.7.

• Fixed bug in subset.subset_bbox that could add unwanted coordinates/dims to some variables when applied to an entire dataset.

• Reformatted packaging configuration to pure Py3 wheel that ignore tests and test data.

• Now officially supporting Python3.8!

• Enhancement to precip_accumulation() to allow estimated amounts solid (or liquid) phase precipitation.

• Bugfix for frequency analysis choking on time series with NaNs only.

v0.10.x-beta (2019-06-18)

• Added indices to ICCLIM module.

• Added indices days_over_precip_thresh and fraction_over_precip_thresh.

• Migrated to a major.minor.patch-release semantic versioning system.

• Removed attributes in netCDF output from Indicators that are not in the CF-convention.

• Added fit indicator to fit the parameters of a distribution to a series.

• Added utilities with ensemble, run length, and subset algorithms to the documentation.

• Source code development standards now implement Python Black formatting.

• Pre-commit is now used to launch code formatting inspections for local development.

• Documentation now includes more detailed usage and an example workflow notebook.

• Development build configurations are now available via both Anaconda and pip install methods.

• Modified create_ensembles() to allow creation of ensemble dataset without a time dimension as well as from xr.Datasets.

• Modified create ensembles() to pad input data with nans when time dimensions are unequal.

• Updated subset_gridpoint() and subset_bbox() to use .sel method if ‘lon’ and ‘lat’ dims are present.

• Added Azure Pipelines to automatically build xclim in Microsoft Windows environments. – REMOVED

• Now employing PEP8 + Black compatible autoformatting.

• Added Windows and macOS images to Travis CI build ensemble.

• Added variable thresholds for tasmax and tasmin in daily_freezethaw_events.

• Updated subset.py to use date formatted strings (“%Y”, “%Y%m” etc.) in temporal subsetting.

• Clean-up of day-of-year resampling. Precipitation percentile threshold will work without a doy index.

• Addressed deprecations for xarray 0.13.0.

• Added a decorator function that verifies validity and reformats subset calls using start_date or end_date signatures.

• Fixed a bug where ‘lon’ or ‘lon_bounds’ would return false values if either signatures were set to 0.

v0.10-beta (2019-06-06)

• Dropped support for Python 2.

• Added support for period of the year subsetting in checks.missing_any.

• Now allow for passing positive longitude values when subsetting data with negative longitudes.

• Improved runlength calculations for small grid size arrays via ufunc_1dim flag.

v0.9-beta (2019-05-13)

This is a significant jump in the release. Many modifications have been made and will be added to the documentation in the coming days. Among the many changes:

• New indices have been added with documentation and call examples.

• Run_length based operations have been optimized.

• Support for CF non-standard calendars.

• Automated/improved unit conversion and management via pint library.

• Added ensemble utilities for creation and analysis of muti-model climate ensembles.

• Added subsetting utilities for spatio-temporal subsets of xarray data objects.

• Added streamflow indicators.

• Refactoring of the code : separation of indices.py into a directory with sub-files (simple, threshold and multivariate); ensembles and subset utilities separated into distinct modules (pulled from utils.py).

• Indicators are now split into packages named by realms. import xclim.atmos to load indicators related to atmospheric variables.

v0.8-beta (2019-02-11)

This was a staging release and is functionally identical to 0.7-beta.

0.7-beta (2019-02-05)

Major Changes:

• Support for resampling of data structured using non-standard CF-Time calendars.

• Added several ICCLIM and other indicators.

• Dropped support for Python 3.4.

• Now under Apache v2.0 license.

• Stable PyPI-based dependencies.

• Dask optimizations for better memory management.

• Introduced class-based indicator calculations with data integrity verification and CF-Compliant-like metadata writing functionality.

Class-based indicators are new methods that allow index calculation with error-checking and provide on-the-fly metadata checks for CF-Compliant (and CF-compliant-like) data that are passed to them. When written to NetCDF, outputs of these indicators will append appropriate metadata based on the indicator, threshold values, moving window length, and time period / resampling frequency examined.

v0.6-alpha (2018-10-03)

• File attributes checks.

• Added daily downsampler function.

• Better documentation on ICCLIM indices.

v0.5-alpha (2018-09-26)

• Added total precipitation indicator.

v0.4-alpha (2018-09-14)

• Fully PEP8 compliant and available under MIT License.

v0.3-alpha (2018-09-4)

• Added icclim module.

• Reworked documentation, docs theme.

v0.2-alpha (2018-08-27)

• Added first indices.

v0.1.0-dev (2018-08-23)

• First release on PyPI.