code: def test_mfx_ftest():
      """test that the mfx ftest indeed runs"""
      n_samples, n_tests = 15, 100
      np.random.seed(1)
  
      # generate some data
      vardata = np.random.rand(n_samples, n_tests)
      data = generate_data(np.ones((n_samples, 1)), 0, 1, vardata)
  
      # compute the test statistics
      f = one_sample_ftest(data, vardata, n_iter=5)
      assert f.shape == (n_tests,)
      assert np.abs(f.mean() - 1) < 1
      assert f.var() < 10
      assert f.var() > 0.2
  
file_path: nipy/nipy/algorithms/statistics/tests/test_mixed_effects.py
imports: import numpy
  import numpy.random
  import pytest
  from numpy.testing import assert_almost_equal, assert_array_almost_equal
  from ..bayesian_mixed_effects import two_level_glm
  from ..mixed_effects_stat import generate_data, mfx_stat, one_sample_ftest, one_sample_ttest, t_stat, two_sample_ftest, two_sample_ttest
label_desc: Use image node_id 6 for calling a global function with example usage: test_mfx_ftest() without return types