code: def von_mises_cdf_normalapprox(k, x):
      b = np.sqrt(2 / np.pi) * np.exp(k) / i0(k)
      z = b * np.sin(x / 2.0)
      return scipy.stats.norm.cdf(z)
  
imports: from __future__ import division, print_function, absolute_import
  import numpy
  import scipy.stats
  from scipy.special import i0
label_desc: Use image node_id 2 for calling a global function with example usage: von_mises_cdf_normalapprox(k, x) and returns: scipy