code: def nct_kurt_bug():
      """test for incorrect kurtosis of nct
  
      D. Hogben, R. S. Pinkham, M. B. Wilk: The Moments of the Non-Central
      t-DistributionAuthor(s): Biometrika, Vol. 48, No. 3/4 (Dec., 1961),
      pp. 465-468
      """
      from numpy.testing import assert_almost_equal
  
      mvsk_10_1 = (1.08372, 1.325546, 0.39993, 1.2499424941142943)
      assert_almost_equal(
          stats.nct.stats(10, 1, moments="mvsk"), mvsk_10_1, decimal=6
      )
      c1 = np.array([1.08372])
      c2 = np.array([0.0755460, 1.25000])
      c3 = np.array([0.0297802, 0.580566])
      c4 = np.array([0.0425458, 1.17491, 6.25])
  
      # calculation for df=10, for arbitrary nc
      nc = 1
      mc1 = c1.item()
      mc2 = (c2 * nc ** np.array([2, 0])).sum()
      mc3 = (c3 * nc ** np.array([3, 1])).sum()
      mc4 = c4 = np.array([0.0425458, 1.17491, 6.25])
      mvsk_nc = mc2mvsk((mc1, mc2, mc3, mc4))
  
file_path: statsmodels/statsmodels/sandbox/distributions/tests/check_moments.py
imports: import numpy
  from scipy import stats
  from statsmodels.sandbox.distributions.sppatch import expect_v2
  from .distparams import distcont
label_desc: Use image node_id 9 for calling a global function with example usage: nct_kurt_bug() without return types