code: def inv_erf(z):
      """
      Inverse error function.
  
      :param z: function input
      :type z: float
      :return: result as float
      """
      if z <= -1 or z >= 1:
          return "None"
      if z == 0:
          return 0
      result = ndtri((z + 1) / 2.0) / math.sqrt(2)
      return result
  
imports: from __future__ import division
  import sys
  import math
  import numpy
  import re
  from .pycm_param import *
  from .pycm_error import pycmMatrixError
  from warnings import warn
  from functools import wraps
label_desc: Use image node_id 28 for calling a global function with example usage: inv_erf(z) and returns: result, str, int