'Check the 2-class multinomial (nominal) GEE fit against
logistic regression.'

def test_multinomial(self):

    np.random.seed(34234)
    endog = np.r_[(0, 0, 0, 0, 1, 1, 1, 1)]
    exog = np.ones((8, 2))
    exog[:, 1] = np.r_[(1, 2, 1, 1, 2, 1, 2, 2)]
    groups = np.arange(8)
    model = sm.NominalGEE(endog, exog, groups)
    results = model.fit(cov_type='naive', start_params=[3.295837, (-2.197225)])
    logit_model = sm.GEE(endog, exog, groups, family=sm.families.Binomial())
    logit_results = logit_model.fit(cov_type='naive')
    assert_allclose(results.params, (- logit_results.params), rtol=1e-05)
    assert_allclose(results.bse, logit_results.bse, rtol=1e-05)
