'Initialize is called by
statsmodels.model.LikelihoodModel.__init__
and should contain any preprocessing that needs to be done for a model.'

def initialize(self):

    self.df_model = float((np_matrix_rank(self.exog) - 1))
    self.df_resid = float((self.exog.shape[0] - np_matrix_rank(self.exog)))
