DOC Mention StandardScaler ddof
@@ -123,6 +123,10 @@ def scale(X, axis=0, with_mean=True, with_std=True, copy=True):
NaNs are treated as missing values: disregarded to compute the statistics,
and maintained during the data transformation.
+ We use a biased estimator for the standard deviation, equivalent to
+ `numpy.std(x, ddof=0)`. Note that the choice of `ddof` is unlikely to
+ affect model performance.
+
For a comparison of the different scalers, transformers, and normalizers,
see :ref:`examples/preprocessing/plot_all_scaling.py
<sphx_glr_auto_examples_preprocessing_plot_all_scaling.py>`.
@@ -575,6 +579,10 @@ class StandardScaler(BaseEstimator, TransformerMixin):
NaNs are treated as missing values: disregarded in fit, and maintained in
transform.
+ We use a biased estimator for the standard deviation, equivalent to
+ `numpy.std(x, ddof=0)`. Note that the choice of `ddof` is unlikely to
+ affect model performance.
+
For a comparison of the different scalers, transformers, and normalizers,
see :ref:`examples/preprocessing/plot_all_scaling.py
<sphx_glr_auto_examples_preprocessing_plot_all_scaling.py>`.
