DOC Clarify how initial conditions are chosen for NMF.
@@ -911,7 +911,8 @@ def non_negative_factorization(X, W=None, H=None, n_components=None, *,
(generally faster, less accurate alternative to NNDSVDa
for when sparsity is not desired)
- - 'custom': use custom matrices W and H
+ - 'custom': use custom matrices W and H if `update_H=True`. If
+ `update_H=False`, then only custom matrix H is used.
.. versionchanged:: 0.23
The default value of `init` changed from 'random' to None in 0.23.
