code: def reldiff(a, b):
      diff = np.abs(a - b)
      norm = np.abs(a)
      reldiff = np.max(diff / (norm + 1e-7))
      return reldiff
  
imports: import os
  import mxnet
  import numpy
  import pickle
label_desc: Use image node_id 2 for calling a global function with example usage: reldiff(a, b) and returns: reldiff