scikit-learn/scikit-learn — pull request #2837 by VirgileFritsch (2014-02-07 16:33:51+00:00)
Title: BF: Correct degrees of freedom in f_regression + test.

Degrees of freedom are equal to 'n - 2' only if we center the variates. Otherwise it should be 'n - 1'.
I use the syntax `... - int(center)` because it is concise but using a `if center: ... else ...` statement instead would afford checking that we actually test it through code coverage.