text: import matplotlib
  from skimage import draw as skd
  import matplotlib.pyplot as plt
  import xray_vision.mpl_plotting as xrv_plt
  import numpy as np
  
  import skxray.roi as roi
  
  frame_shape = (128, 128)
  
  test_image = np.zeros(frame_shape)
  r = 5
  
  for n, (i, j) in enumerate(zip([5, 15, 40, 110],
                                 [120, 10, 50, 80]), 1):
      rr, cc = skd.circle(i, j, r, shape=frame_shape)
      test_image[rr, cc] = n
  
  
  fig, ax = plt.subplots()
  xrv_plt.roi.show_label_array(ax, test_image)
  
  # make some sample data
  x = np.linspace(-2, 2, 100)
  X, Y = np.meshgrid(x, x)
  Z = 100*np.cos(np.sqrt(x**2 + Y**2))**2 + 50
  
  inner_radius = 10   # radius of the first ring
  width = 4           # width of each ring
  spacing = 4         # no spacing between rings
  num_rings = 3       # number of rings
  center = (50, 50)   # center of the image
  
  #  find the edges of the required rings
  edges = roi.ring_edges(inner_radius, width, spacing, num_rings)
  
  # create a label array
  rings = roi.rings(edges, center, Z.shape)
  
  fig, ax = plt.subplots()
  xrv_plt.roi.show_label_array_on_image(ax, Z, rings)
  