Resampling indicator (#927)

* Resampling indicator

* upd hist

* Update xclim/core/indicator.py

Co-authored-by: David Huard <[email protected]>

* Add a few semi-related tests

Co-authored-by: Trevor James Smith <[email protected]>
Co-authored-by: David Huard <[email protected]>

HISTORY.rst

@@ -9,12 +9,14 @@ Contributors to this version: Pascal Bourgault (:user:`aulemahal`), Travis Logan
 New features and enhancements
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Added an optimized pathway for ``xclim.indices.run_length`` functions when ``window=1``. (:pull:`911`, :issue:`910`).
+* The data input frequency expected by ``Indicator``s is now in the ``src_freq`` attribute and is thus controlable by subclassing existing indicators. (:issue:`898`, :pull:`927`).
 
 Internal changes
 ~~~~~~~~~~~~~~~~
 * Removed some logging configurations in ``dataflags`` that were polluting python's main logging configuration. (:pull:`909`).
 * Synchronized logging formatters in `xclim.ensembles` and `xclim.core.utils`. (:pull:`909`).
 * Added a helper function for generating the release notes with dynamically-generated ReStructuredText or Markdown-formatted hyperlinks (:pull:`922`, :issue:`907`).
+* Split of resampling-related functionality of ``Indicator``s into a new ``ResamplingIndicator`` subclass. The use of new (private) methods makes it easier to inject functionality in indicator subclasses. (:issue:`867`, :pull:`927`).
 
 Bug fixes
 ~~~~~~~~~

xclim/core/datachecks.py

@@ -35,23 +35,23 @@ def check_freq(var: xr.DataArray, freq: Union[str, Sequence[str]], strict: bool
     exp_base = [parse_offset(frq)[1] for frq in freq]
     v_freq = xr.infer_freq(var.time)
     if v_freq is None:
-        raise ValidationError("Unable to infer the frequency of the time series.")
+        raise ValidationError(
+            "Unable to infer the frequency of the time series. "
+            "To mute this, set xclim's option data_validation='log'."
+        )
     v_base = parse_offset(v_freq)[1]
     if v_base not in exp_base or (
         strict and all(compare_offsets(v_freq, "!=", frq) for frq in freq)
     ):
         raise ValidationError(
-            f"Frequency of time series not {'strictly' if strict else ''} in {freq}"
+            f"Frequency of time series not {'strictly' if strict else ''} in {freq}. "
+            "To mute this, set xclim's option data_validation='log'."
         )
 
 
-@datacheck
 def check_daily(var: xr.DataArray):
     """Raise an error if not series has a frequency other that daily, or is not monotonically increasing.
 
     Note that this does not check for gaps in the series.
     """
-    if xr.infer_freq(var.time) != "D":
-        raise ValidationError(
-            "time series is not recognized as daily. You can quiet this error by setting `data_validation` to 'warn' or 'log', in `xclim.set_options`."
-        )
+    return check_freq(var, "D")

xclim/core/formatting.py

@@ -541,8 +541,10 @@ def generate_indicator_docstring(ind):
     """
     header = f"{ind.title} (realm: {ind.realm})\n\n{ind.abstract}\n"
 
-    special = f'This indicator will check for missing values according to the method "{ind.missing}".\n'
+    special = ""
 
+    if hasattr(ind, "missing"):  # Only ResamplingIndicators
+        special += f'This indicator will check for missing values according to the method "{ind.missing}".\n'
     if hasattr(ind.compute, "__module__"):
         special += f"Based on indice :py:func:`~{ind.compute.__module__}.{ind.compute.__name__}`.\n"
         if ind.injected_parameters:
@@ -554,7 +556,9 @@ def generate_indicator_docstring(ind):
     if ind.keywords:
         special += f"Keywords : {ind.keywords}.\n"
 
-    parameters = _gen_parameters_section(ind.parameters, ind.allowed_periods)
+    parameters = _gen_parameters_section(
+        ind.parameters, getattr(ind, "allowed_periods", None)
+    )
 
     returns = _gen_returns_section(ind.cf_attrs)