DOC: document resulting NaN in SimpleImputer.statistics_
@@ -137,6 +137,9 @@ class SimpleImputer(BaseEstimator, TransformerMixin):
----------
statistics_ : array of shape (n_features,)
The imputation fill value for each feature.
+ Computing statistics can result in `np.nan` values.
+ During `transform`, features corresponding to `np.nan`
+ statistics will be discarded.
indicator_ : :class:`sklearn.impute.MissingIndicator`
Indicator used to add binary indicators for missing values.
