code: def normal_cdf(x, mu, sigma):
      top = x - mu
      bottom = np.maximum(np.sqrt(2) * sigma, EPS)
      z = old_div(top, bottom)
      return 0.5 * (1 + erf(z))
  
imports: from __future__ import print_function
  from __future__ import absolute_import
  from __future__ import division
  from builtins import str
  from builtins import map
  from builtins import zip
  from builtins import range
  from past.utils import old_div
  import logging
  import time
  import numpy
  from scipy.special import erf
  from .None import pyll
  from .pyll import scope
  from .pyll.stochastic import implicit_stochastic
  from .base import miscs_to_idxs_vals
  from .base import miscs_update_idxs_vals
  from .None import rand
label_desc: Use image node_id 4 for calling a global function with example usage: normal_cdf(x, mu, sigma) and returns: unknown