Remove change_significance (#1737)

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### Pull Request Checklist:
- [ ] This PR addresses an already opened issue (for bug fixes /
features)
    - This PR fixes #xyz
- [ ] Tests for the changes have been added (for bug fixes / features)
- [x] (If applicable) Documentation has been added / updated (for bug
fixes / features)
- [ ] CHANGES.rst has been updated (with summary of main changes)
- [ ] Link to issue (:issue:`number`) and pull request (:pull:`number`)
has been added

### What kind of change does this PR introduce?

* `change_significance` was marked as deprecated in 0.47, to be removed
in 0.49, which is the next version.

### Does this PR introduce a breaking change?
Technically, no.


### Other information:

CHANGES.rst

@@ -22,9 +22,11 @@ New indicators
 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 These functions have been replaced by ``xclim.core.calendar.stack_periods`` and ``xclim.core.calendar.unstack_periods``. (:pull:`1717`).
+* The previously deprecated function ``xclim.ensembles.change_significance`` has been removed. (:pull:`1737`).
 * Indicators ``snw_season_length`` and ``snd_season_length`` have been modified, see above.
 * The `hargeaves85`/`hg85` method for the ``potential_evapotranspiration`` indicator and indice has been modified for precision and consistency with recent academic literature. (:issue:`1710`, :pull:`1723`).
 
+
 Bug fixes
 ^^^^^^^^^
 * Fixed an bug in sdba's ``map_groups`` that prevented passing DataArrays with cftime coordinates if the ``sdba_encode_cf`` option was True. (:issue:`1673`, :pull:`1674`).

docs/api.rst

@@ -59,9 +59,6 @@ Ensembles Module
 .. autofunction:: xclim.ensembles.robustness_categories
    :noindex:
 
-.. autofunction:: xclim.ensembles.change_significance
-   :noindex:
-
 .. autofunction:: xclim.ensembles.robustness_coefficient
    :noindex:
 

xclim/ensembles/__init__.py

@@ -19,7 +19,6 @@
     plot_rsqprofile,
 )
 from ._robustness import (
-    change_significance,
     robustness_categories,
     robustness_coefficient,
     robustness_fractions,

xclim/ensembles/_robustness.py

@@ -9,7 +9,6 @@
 
 from __future__ import annotations
 
-import warnings
 from inspect import Parameter, signature
 
 import numpy as np
@@ -20,7 +19,6 @@
 from xclim.indices.generic import compare, detrend
 
 __all__ = [
-    "change_significance",
     "robustness_categories",
     "robustness_coefficient",
     "robustness_fractions",
@@ -33,7 +31,7 @@
 New tests must be decorated with :py:func:`significance_test` and fulfill the following requirements:
 
 - Function name should begin by "_", registered test name is the function name without its first character and with _ replaced by -.
-- Function must accept 2 positional arguments : fut and ref (see :py:func:`change_significance` for definitions)
+- Function must accept 2 positional arguments : fut and ref (see :py:func:`robustness_fractions` for definitions)
 - Function may accept other keyword-only arguments.
 - Function must return 2 values :
     + `changed` : 1D boolean array along `realization`. True for realization with significant change.
@@ -42,7 +40,7 @@
 
 
 def significance_test(func):
-    """Register a significance test for use in :py:func:`change_significance`.
+    """Register a significance test for use in :py:func:`robustness_fractions`.
 
     See :py:data:`SIGNIFICANCE_TESTS`.
     """
@@ -294,67 +292,6 @@ def robustness_fractions(  # noqa: C901
     return out
 
 
-def change_significance(  # noqa: C901
-    fut: xr.DataArray | xr.Dataset,
-    ref: xr.DataArray | xr.Dataset,
-    test: str | None = "ttest",
-    weights: xr.DataArray | None = None,
-    p_vals: bool = False,
-    **kwargs,
-) -> (
-    tuple[xr.DataArray | xr.Dataset, xr.DataArray | xr.Dataset]
-    | tuple[
-        xr.DataArray | xr.Dataset,
-        xr.DataArray | xr.Dataset,
-        xr.DataArray | xr.Dataset | None,
-    ]
-):
-    """Backwards-compatible implementation of :py:func:`robustness_fractions`."""
-    warnings.warn(
-        (
-            "Function change_significance is deprecated as of xclim 0.47 and will be removed in 0.49. "
-            "Please use robustness_fractions instead."
-        ),
-        FutureWarning,
-    )
-
-    if isinstance(fut, xr.Dataset):
-        outs = {
-            v: robustness_fractions(
-                fut[v],
-                ref[v] if isinstance(ref, xr.Dataset) else ref,
-                test=test,
-                weights=weights[v] if isinstance(weights, xr.Dataset) else weights,
-                **kwargs,
-            )
-            for v in fut.data_vars.keys()
-        }
-        change_frac = xr.merge([fracs.changed.rename(v) for v, fracs in outs.items()])
-        pos_frac = xr.merge(
-            [
-                (fracs.changed_positive / fracs.changed).rename(v)
-                for v, fracs in outs.items()
-            ]
-        )
-        if p_vals:
-            if "pvals" in list(outs.values())[0]:
-                pvals = xr.merge([fracs.pvals.rename(v) for v, fracs in outs.items()])
-            else:
-                pvals = None
-            return change_frac, pos_frac, pvals
-        return change_frac, pos_frac
-
-    fracs = robustness_fractions(fut, ref, test=test, weights=weights, **kwargs)
-    # different def.
-    # Old "pos_frac" is fraction of change_frac that is positive
-    # New change_pos_frac is fraction of all that is both positive and significant
-    pos_frac = fracs.changed_positive / fracs.changed
-
-    if p_vals:
-        return fracs.changed, pos_frac, fracs.pvals if "pvals" in fracs else None
-    return fracs.changed, pos_frac
-
-
 def robustness_categories(
     changed_or_fractions: xr.Dataset | xr.DataArray,
     agree: xr.DataArray | None = None,
@@ -667,7 +604,7 @@ def _ipcc_ar6_c(fut, ref, *, ref_pi=None):
     return changed, None
 
 
-# Add doc of each significance test to the `change_significance` output.
+# Add doc of each significance test to `robustness_fractions` output's doc.
 def _gen_test_entry(namefunc):
     name, func = namefunc
     doc = func.__doc__.replace("\n    ", "\n\t\t").rstrip()