Add nan warning in get_bitinformation; Closes #200

CHANGELOG.rst

@@ -4,7 +4,7 @@ CHANGELOG
 
 X.X.X (unreleased)
 ------------------
-
+* Add nan warning in :py:func:`xbitinfo.xbitinfo.get_bitinformation` (:issue:`200`, :pr:`260`) `Timothy Hodson` _.
 * Add support for additional datatypes in :py:func:`xbitinfo.xbitinfo.plot_bitinformation` (:pr:`218`, :issue:`168`) `Hauke Schulz`_.
 * Drop python 3.8 support and add python 3.11 (:pr:`175`) `Hauke Schulz`_.
 * Implement basic retrieval of bitinformation in python as alternative to julia implementation (:pr:`156`, :issue:`155`, :pr:`126`, :issue:`125`) `Hauke Schulz`_ with helpful comments from `Milan Klöwer`_.

tests/test_get_bitinformation.py

@@ -1,5 +1,6 @@
 """Tests for `xbitinfo` package."""
 import os
+import warnings
 
 import numpy as np
 import pytest
@@ -215,6 +216,14 @@ def test_get_bitinformation_dim_list(rasm, implementation):
     assert (bi.dim == ["x", "y"]).all()
 
 
+def test_get_bitinformation_nan_warning():
+    data = xr.Dataset({"var": ("x", np.array([1, 2, np.nan, 4, 5]))})
+
+    with warnings.catch_warnings(record=True) as w:
+        xb.get_bitinformation(data, implementation="python")
+        assert len(w) >= 1
+
+
 def test_get_bitinformation_keep_attrs(rasm):
     bi = xb.get_bitinformation(rasm, dim=["x", "y"]).Tair
     assert "units" in bi.attrs

xbitinfo/xbitinfo.py

@@ -1,6 +1,7 @@
 import json
 import logging
 import os
+import warnings
 
 import numpy as np
 import xarray as xr
@@ -184,6 +185,8 @@ def get_bitinformation(  # noqa: C901
     """
     if implementation == "julia" and not julia_installed:
         raise ImportError('Please install julia or use implementation="python".')
+    if ds.isnull().any():
+        warnings.warn("This dataset contains NaNs, which can yield unexpected results.")
     if dim is None and axis is None:
         # gather bitinformation on all axis
         return _get_bitinformation_along_dims(