code: def patCircles(s0):
      '''make circle array'''
      arr = np.zeros((s0,s0), dtype=np.uint8)
      col = 255
      for rad in np.linspace(s0,s0/7.,10):
          cv2.circle(arr, (0,0), int(round(rad)), color=col, 
                     thickness=-1, lineType=cv2.LINE_AA )
          if col:
              col = 0
          else:
              col = 255
              
  
      return arr.astype(floatf patCircles(s0):
      '''make circle array'''
      arr = np.zeros((s0,s0), dtype=np.uint8)
      col = 255
      for rad in np.linspace(s0,s0/7.,10):
          cv2.circle(arr, (0,0), int(round(rad)), color=col, 
                     thickness=-1, lineType=cv2.LINE_AA )
          if col:
              col = 0
          else:
              col = 255
              
  
      return arr.astype(float)
docs: make circle array