'Perturbs the model\'s parameters using a bootstrap.'

def _perturb_bootstrap(self, vname):

    (endog, exog, init_kwds, fit_kwds) = self.get_fitting_data(vname)
    m = len(endog)
    rix = np.random.randint(0, m, m)
    endog = endog[rix]
    exog = exog[rix, :]
    init_kwds = self._boot_kwds(init_kwds, rix)
    fit_kwds = self._boot_kwds(fit_kwds, rix)
    klass = self.model_class[vname]
    self.models[vname] = klass(endog, exog, **init_kwds)
    self.results[vname] = self.models[vname].fit(**fit_kwds)
    self.params[vname] = self.results[vname].params
