# What’s New¶

## climpred v2.0.0 (2020-01-22)¶

### New Features¶

- Add support for
`days`

,`pentads`

,`weeks`

,`months`

,`seasons`

for lead time resolution.`climpred`

now requires a`lead`

attribute “units” to decipher what resolution the predictions are at. (GH#294) Kathy Pegion and Riley X. Brady.

```
>>> hind = climpred.tutorial.load_dataset('CESM-DP-SST')
>>> hind.lead.attrs['units'] = 'years'
```

`HindcastEnsemble`

now has`.add_observations()`

and`.get_observations()`

methods. These are the same as`.add_reference()`

and`.get_reference()`

, which will be deprecated eventually. The name change clears up confusion, since “reference” is the appropriate name for a reference forecast, e.g. persistence. (GH#310) Riley X. Brady.`HindcastEnsemble`

now has`.verify()`

function, which duplicates the`.compute_metric()`

function. We feel that`.verify()`

is more clear and easy to write, and follows the terminology of the field. (GH#310) Riley X. Brady.`e2o`

and`m2o`

are now the preferred keywords for comparing hindcast ensemble means and ensemble members to verification data, respectively. (GH#310) Riley X. Brady.

### Documentation¶

New example pages for subseasonal-to-seasonal prediction using

`climpred`

. (GH#294) Kathy PegionComparisons page rewritten for more clarity. (GH#310) Riley X. Brady.

### Bug Fixes¶

- Fixed m2m broken comparison issue and removed correction (GH#290) Aaron Spring.

### Internals/Minor Fixes¶

- Updates to
`xskillscore`

v0.0.12 to get a 30-50% speedup in compute functions that rely on metrics from there. (GH#309) Riley X. Brady. - Stacking dims is handled by
`comparisons`

, no need for internal keyword`stack_dims`

. Therefore`comparison`

now takes`metric`

as argument instead. (GH#290) Aaron Spring. `assign_attrs`

now carries dim (GH#290) Aaron Spring.- “reference” changed to “verif” throughout hindcast compute functions. This is more clear, since “reference” usually refers to a type of forecast, such as persistence. (GH#310) Riley X. Brady.
`Comparison`

objects can now have aliases. (GH#310) Riley X. Brady.

## climpred v1.2.1 (2020-01-07)¶

### Depreciated¶

`mad`

no longer a keyword for the median absolute error metric. Users should now use`median_absolute_error`

, which is identical to changes in`xskillscore`

version 0.0.10. (GH#283) Riley X. Brady`pacc`

no longer a keyword for the p value associated with the Pearson product-moment correlation, since it is used by the correlation coefficient. (GH#283) Riley X. Brady`msss`

no longer a keyword for the Murphy’s MSSS, since it is reserved for the standard MSSS. (GH#283) Riley X. Brady

### New Features¶

Metrics

`pearson_r_eff_p_value`

and`spearman_r_eff_p_value`

account for autocorrelation in computing p values. (GH#283) Riley X. BradyMetric

`effective_sample_size`

computes number of independent samples between two time series being correlated. (GH#283) Riley X. BradyAdded keywords for metrics: (GH#283) Riley X. Brady

`'pval'`

for`pearson_r_p_value`

`['n_eff', 'eff_n']`

for`effective_sample_size`

`['p_pval_eff', 'pvalue_eff', 'pval_eff']`

for`pearson_r_eff_p_value`

`['spvalue', 'spval']`

for`spearman_r_p_value`

`['s_pval_eff', 'spvalue_eff', 'spval_eff']`

for`spearman_r_eff_p_value`

`'nev'`

for`nmse`

### Internals/Minor Fixes¶

`climpred`

now requires`xarray`

version 0.14.1 so that the`drop_vars()`

keyword used in our package does not throw an error. (GH#276) Riley X. Brady- Update to
`xskillscore`

version 0.0.10 to fix errors in weighted metrics with pairwise NaNs. (GH#283) Riley X. Brady `doc8`

added to`pre-commit`

to have consistent formatting on`.rst`

files. (GH#283) Riley X. Brady- Remove
`proper`

attribute on`Metric`

class since it isn’t used anywhere. (GH#283) Riley X. Brady - Add testing for effective p values. (GH#283) Riley X. Brady
- Add testing for whether metric aliases are repeated/overwrite each other. (GH#283) Riley X. Brady
`ppp`

changed to`msess`

, but keywords allow for`ppp`

and`msss`

still. (GH#283) Riley X. Brady

### Documentation¶

- Expansion of metrics documentation with much more detail on how metrics are computed, their keywords, references, min/max/perfect scores, etc. (GH#283) Riley X. Brady
- Update terminology page with more information on metrics terminology. (GH#283) Riley X. Brady

## climpred v1.2.0 (2019-12-17)¶

### Depreciated¶

- Abbreviation
`pval`

depreciated. Use`p_pval`

for`pearson_r_p_value`

instead. (GH#264) Aaron Spring.

### New Features¶

Users can now pass a custom

`metric`

or`comparison`

to compute functions. (GH#268) Aaron Spring.New deterministic metrics (see metrics). (GH#264) Aaron Spring.

- Spearman ranked correlation (spearman_r)
- Spearman ranked correlation p-value (spearman_r_p_value)
- Mean Absolute Deviation (mad)
- Mean Absolute Percent Error (mape)
- Symmetric Mean Absolute Percent Error (smape)

Users can now apply arbitrary

`xarray`

methods to`HindcastEnsemble`

and`PerfectModelEnsemble`

. (GH#243) Riley X. Brady.Add “getter” methods to

`HindcastEnsemble`

and`PerfectModelEnsemble`

to retrieve`xarray`

datasets from the objects. (GH#243) Riley X. Brady.>>> hind = climpred.tutorial.load_dataset('CESM-DP-SST') >>> ref = climpred.tutorial.load_dataset('ERSST') >>> hindcast = climpred.HindcastEnsemble(hind) >>> hindcast = hindcast.add_reference(ref, 'ERSST') >>> print(hindcast) <climpred.HindcastEnsemble> Initialized Ensemble: SST (init, lead, member) float64 ... ERSST: SST (time) float32 ... Uninitialized: None >>> print(hindcast.get_initialized()) <xarray.Dataset> Dimensions: (init: 64, lead: 10, member: 10) Coordinates: * lead (lead) int32 1 2 3 4 5 6 7 8 9 10 * member (member) int32 1 2 3 4 5 6 7 8 9 10 * init (init) float32 1954.0 1955.0 1956.0 1957.0 ... 2015.0 2016.0 2017.0 Data variables: SST (init, lead, member) float64 ... >>> print(hindcast.get_reference('ERSST')) <xarray.Dataset> Dimensions: (time: 61) Coordinates: * time (time) int64 1955 1956 1957 1958 1959 ... 2011 2012 2013 2014 2015 Data variables: SST (time) float32 ...

`metric_kwargs`

can be passed to`Metric`

. (GH#264) Aaron Spring.- See
`metric_kwargs`

under metrics.

- See

### Bug Fixes¶

`compute_metric()`

doesn’t drop coordinates from the initialized hindcast ensemble anymore. (GH#258) Aaron Spring.- Metric
`uacc`

does not crash when`ppp`

negative anymore. (GH#264) Aaron Spring. - Update
`xskillscore`

to version 0.0.9 to fix all-NaN issue with`pearson_r`

and`pearson_r_p_value`

when there’s missing data. (GH#269) Riley X. Brady.

### Internals/Minor Fixes¶

Rewrote

`varweighted_mean_period()`

based on`xrft`

. Changed`time_dim`

to`dim`

. Function no longer drops coordinates. (GH#258) Aaron SpringAdd

`dim='time'`

in`dpp()`

. (GH#258) Aaron SpringComparisons

`m2m`

,`m2e`

rewritten to not stack dims into supervector because this is now done in`xskillscore`

. (GH#264) Aaron SpringAdd

`tqdm`

progress bar to`bootstrap_compute()`

. (GH#244) Aaron SpringRemove inplace behavior for

`HindcastEnsemble`

and`PerfectModelEnsemble`

. (GH#243) Riley X. BradyAdded tests for chunking with

`dask`

. (GH#258) Aaron SpringFix test issues with esmpy 8.0 by forcing esmpy 7.1 (GH#269). Riley X. Brady

Rewrote

`metrics`

and`comparisons`

as classes to accomodate custom metrics and comparisons. (GH#268) Aaron Spring

### Documentation¶

- Add examples notebook for temporal and spatial smoothing. (GH#244) Aaron Spring
- Add documentation for computing a metric over a specified dimension. (GH#244) Aaron Spring
- Update API to be more organized with individual function/class pages. (GH#243) Riley X. Brady.
- Add page describing the
`HindcastEnsemble`

and`PerfectModelEnsemble`

objects more clearly. (GH#243) Riley X. Brady - Add page for publications and helpful links. (GH#270) Riley X. Brady.

## climpred v1.1.0 (2019-09-23)¶

### Features¶

- Write information about skill computation to netcdf attributes(GH#213) Aaron Spring
- Temporal and spatial smoothing module (GH#224) Aaron Spring
- Add metrics brier_score, threshold_brier_score and crpss_es (GH#232) Aaron Spring
- Allow compute_hindcast and compute_perfect_model to specify which dimension dim to calculate metric over (GH#232) Aaron Spring

### Bug Fixes¶

- Correct implementation of probabilistic metrics from xskillscore in compute_perfect_model, bootstrap_perfect_model, compute_hindcast and bootstrap_hindcast, now requires xskillscore>=0.05 (GH#232) Aaron Spring

### Internals/Minor Fixes¶

- Rename .stats.DPP to dpp (GH#232) Aaron Spring
- Add matplotlib as a main dependency so that a direct pip installation works (GH#211) Riley X. Brady.
`climpred`

is now installable from conda-forge (GH#212) Riley X. Brady.- Fix erroneous descriptions of sample datasets (GH#226) Riley X. Brady.
- Benchmarking time and peak memory of compute functions with asv (GH#231) Aaron Spring

### Documentation¶

- Add scope of package to docs for clarity for users and developers. (GH#235) Riley X. Brady.

## climpred v1.0.1 (2019-07-04)¶

### Bug Fixes¶

- Accomodate for lead-zero within the
`lead`

dimension (GH#196) Riley X. Brady. - Fix issue with adding uninitialized ensemble to
`HindcastEnsemble`

object (GH#199) Riley X. Brady. - Allow
`max_dof`

keyword to be passed to`compute_metric`

and`compute_persistence`

for`HindcastEnsemble`

(GH#199) Riley X. Brady.

### Internals/Minor Fixes¶

- Force
`xskillscore`

version 0.0.4 or higher to avoid`ImportError`

(GH#204) Riley X. Brady. - Change
`max_dfs`

keyword to`max_dof`

(GH#199) Riley X. Brady. - Add testing for
`HindcastEnsemble`

and`PerfectModelEnsemble`

(GH#199) Riley X. Brady

## climpred v1.0.0 (2019-07-03)¶

`climpred`

v1.0.0 represents the first stable release of the package. It includes
`HindcastEnsemble`

and `PerfectModelEnsemble`

objects to perform analysis with.
It offers a suite of deterministic and probabilistic metrics that are optimized to be
run on single time series or grids of data (e.g., lat, lon, and depth). Currently,
`climpred`

only supports annual forecasts.

### Features¶

- Bootstrap prediction skill based on resampling with replacement consistently in
`ReferenceEnsemble`

and`PerfectModelEnsemble`

. (GH#128) Aaron Spring - Consistent bootstrap function for
`climpred.stats`

functions via`bootstrap_func`

wrapper. (GH#167) Aaron Spring - many more metrics:
`_msss_murphy`

,`_less`

and probabilistic`_crps`

,`_crpss`

(GH#128) Aaron Spring

### Bug Fixes¶

`compute_uninitialized`

now trims input data to the same time window. (GH#193) Riley X. Brady`rm_poly`

now properly interpolates/fills NaNs. (GH#192) Riley X. Brady

### Internals/Minor Fixes¶

- The
`climpred`

version can be printed. (GH#195) Riley X. Brady - Constants are made elegant and pushed to a separate module. (GH#184) Andrew Huang
- Checks are consolidated to their own module. (GH#173) Andrew Huang

### Documentation¶

- Documentation built extensively in multiple PRs.

## climpred v0.3 (2019-04-27)¶

`climpred`

v0.3 really represents the entire development phase leading up to the
version 1 release. This was done in collaboration between Riley X. Brady,
Aaron Spring, and Andrew Huang. Future releases will have less additions.

### Features¶

Introduces object-oriented system to

`climpred`

, with classes`ReferenceEnsemble`

and`PerfectModelEnsemble`

. (GH#86) Riley X. BradyExpands bootstrapping module for perfect-module configurations. (GH#78, GH#87) Aaron Spring

Adds functions for computing Relative Entropy (GH#73) Aaron Spring

Sets more intelligible dimension expectations for

`climpred`

(GH#98, GH#105) Riley X. Brady and Aaron Spring:`init`

: initialization dates for the prediction ensemble`lead`

: retrospective forecasts from prediction ensemble; returned dimension for prediction calculations`time`

: time dimension for control runs, references, etc.`member`

: ensemble member dimension.

Updates

`open_dataset`

to display available dataset names when no argument is passed. (GH#123) Riley X. BradyChange

`ReferenceEnsemble`

to`HindcastEnsemble`

. (GH#124) Riley X. BradyAdd probabilistic metrics to

`climpred`

. (GH#128) Aaron SpringConsolidate separate perfect-model and hindcast functions into singular functions (GH#128) Aaron Spring

Add option to pass proxy through to

`open_dataset`

for firewalled networks. (GH#138) Riley X. Brady

### Bug Fixes¶

`xr_rm_poly`

can now operate on Datasets and with multiple variables. It also interpolates across NaNs in time series. (GH#94) Andrew Huang- Travis CI,
`treon`

, and`pytest`

all run for automated testing of new features. (GH#98, GH#105, GH#106) Riley X. Brady and Aaron Spring - Clean up
`check_xarray`

decorators and make sure that they work. (GH#142) Andrew Huang - Ensures that
`help()`

returns proper docstring even with decorators. (GH#149) Andrew Huang - Fixes bootstrap so p values are correct. (GH#170) Aaron Spring

### Internals/Minor Fixes¶

- Adds unit testing for all perfect-model comparisons. (GH#107) Aaron Spring
- Updates CESM-LE uninitialized ensemble sample data to have 34 members. (GH#113) Riley X. Brady
- Adds MPI-ESM hindcast, historical, and assimilation sample data. (GH#119) Aaron Spring
- Replaces
`check_xarray`

with a decorator for checking that input arguments are xarray objects. (GH#120) Andrew Huang - Add custom exceptions for clearer error reporting. (GH#139) Riley X. Brady
- Remove “xr” prefix from stats module. (GH#144) Riley X. Brady
- Add codecoverage for testing. (GH#152) Riley X. Brady
- Update exception messages for more pretty error reporting. (GH#156) Andrew Huang
- Add
`pre-commit`

and`flake8`

/`black`

check in CI. (GH#163) Riley X. Brady - Change
`loadutils`

module to`tutorial`

and`open_dataset`

to`load_dataset`

. (GH#164) Riley X. Brady - Remove predictability horizon function to revisit for v2. (GH#165) Riley X. Brady
- Increase code coverage through more testing. (GH#167) Aaron Spring
- Consolidates checks and constants into modules. (GH#173) Andrew Huang

## climpred v0.2 (2019-01-11)¶

Name changed to `climpred`

, developed enough for basic decadal prediction tasks on a
perfect-model ensemble and reference-based ensemble.

## climpred v0.1 (2018-12-20)¶

Collaboration between Riley Brady and Aaron Spring begins.