code: def velo(dsi, dsf):
      velo = dsi / dsf
      return velo
  
imports: import pytest
  import numpy
  import pandas
  from pandas.testing import assert_frame_equal
  from deepgraph import DeepGraph
label_desc: Use image node_id 3 for calling a global function with example usage: velo(dsi, dsf) and returns: velo