code: def time_ratio(t0, t1):
      if t1 == 0:
          return np.inf
      else:
          return t0 / t1
  
imports: import time
  import numpy
  from ..None import copy_vector
label_desc: Use image node_id 1 for calling a global function with example usage: time_ratio(t0, t1) and returns: np, unknown