'Returns a DataFrame summarizing the marginal effects.
Parameters
alpha : float
Number between 0 and 1. The confidence intervals have the
probability 1-alpha.
Returns
frame : DataFrames
A DataFrame summarizing the marginal effects.'

def summary_frame(self, alpha=0.05):

    _check_at_is_all(self.margeff_options)
    from pandas import DataFrame
    names = [_transform_names[self.margeff_options['method']], 'Std.    Err.', 'z', 'Pr(>|z|)', 'Conf.    Int.    Low', 'Cont.    Int.    Hi.']
    ind = (self.results.model.exog.var(0) != 0)
    exog_names = self.results.model.exog_names
    var_names = [name for (i, name) in enumerate(exog_names) if ind[i]]
    table = np.column_stack((self.margeff, self.margeff_se, self.tvalues, self.pvalues, self.conf_int(alpha)))
    return DataFrame(table, columns=names, index=var_names)
