DOC add detail about flip_y parameter in make_classification
@@ -102,7 +102,8 @@ def make_classification(n_samples=100, n_features=20, n_informative=2,
flip_y : float, optional (default=0.01)
The fraction of samples whose class is assigned randomly. Larger
values introduce noise in the labels and make the classification
- task harder.
+ task harder. Note that the default setting flip_y > 0 might lead
+ to less than n_classes in y in some cases.
class_sep : float, optional (default=1.0)
The factor multiplying the hypercube size. Larger values spread
