code: def fail_r_shape(dsi, sf_s, sf_t, sources, targets):
      dsf = sf_t - sf_s
      velo = dsi / dsf
      sources = sources[dsf <= 1]
      targets = targets[dsf <= 1]
      # the length of dsf must not be modified
      dsf = dsf[:-1]
      return dsf, velo, sources, targets
  
imports: import pytest
  import numpy
  import pandas
  from pandas.testing import assert_frame_equal
  from deepgraph import DeepGraph
label_desc: Use image node_id 11 for calling a global function with example usage: fail_r_shape(dsi, sf_s, sf_t, sources, targets) and returns: dsf,  velo,  sources,  targets