code: def test_t_test():
      """test that the t test run"""
      n_samples, n_tests = 15, 100
      data = nr.randn(n_samples, n_tests)
      t = t_stat(data)
      assert t.shape == (n_tests,)
      assert np.abs(t.mean() < 5 / np.sqrt(n_tests))
      assert t.var() < 2
      assert t.var() > 0.5
  
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 2 for calling a global function with example usage: test_t_test() without return types