statsmodels/statsmodels — pull request #1867 by josef-pkt (2014-08-03 20:34:23+00:00)
Title: Ref covtype fit

integrating robust covariances into the model fit method, see issue #1418

first part: linear models - roughly finished

needed new df_resid_inference to separate df_resid used in scale from df_resid used in t, f tests and similar inference.