fixing invers_transform for WeightedRobustScaler

utils.py

@@ -216,6 +216,15 @@ class WeightedRobustScaler(RobustScaler):
             return super(WeightedRobustScaler, self).transform(X)
 
 
+    def inverse_transform(self, X):
+        if np.isnan(X).any():
+            X *= self.scale_
+            X += self.center_
+            return X
+        else:
+            return super(WeightedRobustScaler, self).inverse_transform(X)
+
+
 def poisson_asimov_significance(s, ds, b, db):
     "see `<http://www.pp.rhul.ac.uk/~cowan/stat/medsig/medsigNote.pdf>`_)"
     db = np.sqrt(db**2+ds**2)