code: def pad_array(in1):
      
  
      padded_size = 2*np.array(in1.shape)
  
      out1 = np.zeros([padded_size[0],padded_size[1]])
      out1[padded_size[0]/4:3*padded_size[0]/4,padded_size[1]/4:3*padded_size[1]/4] = in1
  
      return out1
docs: Simple convenience function to pad arrays for linear convolution.
  
      INPUTS:
      in1     (no default):   Input array which is to be padded.
  
      OUTPUTS:
      out1                    Padded version of the input.