code: def test_dietox(self):
      # dietox data from geepack using random intercepts
      #
      # Fit in R using
      #
      # library(geepack)
      # rm = lmer(Weight ~ Time + (1 | Pig), data=dietox)
      # rm = lmer(Weight ~ Time + (1 | Pig), REML=FALSE, data=dietox)
      #
      # Comments below are R code used to extract the numbers used
      # for comparison.
  
      cur_dir = os.path.dirname(os.path.abspath(__file__))
      rdir = os.path.join(cur_dir, "results")
      fname = os.path.join(rdir, "dietox.csv")
  
      # REML
      data = pd.read_csv(fname)
      model = MixedLM.from_formula(
          "Weight ~ Time", groups="Pig", data=data
      )
      result = model.fit()
  
      # fixef(rm)
      assert_allclose(
          result.fe_params, np.r_[15.723523, 6.942505], rtol=1e-5
      )
  
      # sqrt(diag(vcov(rm)))
      assert_allclose(
          result.bse[0:2], np.r_[0.78805374, 0.03338727], rtol=1e-5
      )
  
      # attr(VarCorr(rm), "sc")^2
      assert_allclose(result.scale, 11.36692, rtol=1e-5)
  
      # VarCorr(rm)[[1]][[1]]
      assert_allclose(result.cov_re, 40.39395, rtol=1e-5)
  
      # logLik(rm)
      assert_allclose(
          model.loglike(result.params_object), -2404.775, rtol=1e-5
      )
  
      # ML
      data = pd.read_csv(fname)
      model = MixedLM.from_formula(
          "Weight ~ Time", groups="Pig", data=data
      )
      result = model.fit(reml=False)
  
      # fixef(rm)
      assert_allclose(
          result.fe_params, np.r_[15.723517, 6.942506], rtol=1e-5
      )
  
      # sqrt(diag(vcov(rm)))
      assert_allclose(
          result.bse[0:2], np.r_[0.7829397, 0.0333661], rtol=1e-5
      )
  
      # attr(VarCorr(rm), "sc")^2
      assert_allclose(result.scale, 11.35251, rtol=1e-5)
  
      # VarCorr(rm)[[1]][[1]]
      assert_allclose(result.cov_re, 39.82097, rtol=1e-5)
  
      # logLik(rm)
      assert_allclose(
          model.loglike(result.params_object), -2402.932, rtol=1e-5
      )
  
imports: from statsmodels.compat.platform import PLATFORM_OSX
  import os
  import csv
  import warnings
  import numpy
  import pandas
  from scipy import sparse
  import pytest
  from statsmodels.regression.mixed_linear_model import MixedLM, MixedLMParams, _smw_solver, _smw_logdet
  from numpy.testing import assert_almost_equal, assert_equal, assert_allclose, assert_
  from statsmodels.base import _penalties
  import statsmodels.tools.numdiff
  from .results import lme_r_results
label_desc: Use image node_id 9 for calling the TestMixedLM obj's underlying member method code with example usage: obj.test_dietox() without return types