text: #! /usr/bin/env python3
  from netCDF4 import Dataset
  from numpy import sum, sqrt
  import sys
  
  case1 = sys.argv[1]
  case2 = sys.argv[2]
  
  data1 = Dataset(case1, 'r')
  theta1 = data1['theta'][2,0,:,:]
  
  data2 = Dataset(case2, 'r')
  theta2 = data2['theta'][2,0,:,:]
  
  diff = sqrt(sum((theta2 - theta1)*(theta2 - theta1)))
  
  if diff < 1.E-6:
    print('### 2D straka test passed. ###')
  else:
    raise ValueError('ERROR: 2D straka test failed. L2-norm is %.2g' % diff)
  