DOC add missing parentheses in TfidfTrasnformer docstring
@@ -966,7 +966,7 @@ class TfidfTransformer(BaseEstimator, TransformerMixin):
If ``smooth_idf=True`` (the default), the constant "1" is added to the
numerator and denominator of the idf as if an extra document was seen
containing every term in the collection exactly once, which prevents
- zero divisions: idf(d, t) = log [ (1 + n) / 1 + df(d, t) ] + 1.
+ zero divisions: idf(d, t) = log [ (1 + n) / (1 + df(d, t)) ] + 1.
Furthermore, the formulas used to compute tf and idf depend
on parameter settings that correspond to the SMART notation used in IR
