fix PolynomialFeatures.powers_ in python 0.16.1

Author: amueller

sklearn/preprocessing/data.py

@@ -20,6 +20,7 @@
 from ..utils.extmath import row_norms
 from ..utils.extmath import _incremental_mean_and_var
 from ..utils.fixes import combinations_with_replacement as combinations_w_r
+from ..utils.fixes import bincount
 from ..utils.sparsefuncs_fast import (inplace_csr_row_normalize_l1,
                                       inplace_csr_row_normalize_l2)
 from ..utils.sparsefuncs import (inplace_column_scale,
@@ -1179,7 +1180,7 @@ def powers_(self):
         combinations = self._combinations(self.n_input_features_, self.degree,
                                           self.interaction_only,
                                           self.include_bias)
-        return np.vstack(np.bincount(c, minlength=self.n_input_features_)
+        return np.vstack(bincount(c, minlength=self.n_input_features_)
                          for c in combinations)
 
     def get_feature_names(self, input_features=None):