text: """
  =====================
  Grayscale style sheet
  =====================
  
  This example demonstrates the "grayscale" style sheet, which changes all colors
  that are defined as `.rcParams` to grayscale. Note, however, that not all
  plot elements respect `.rcParams`.
  """
  
  import numpy as np
  import matplotlib.pyplot as plt
  
  # Fixing random state for reproducibility
  np.random.seed(19680801)
  
  
  def color_cycle_example(ax):
      L = 6
      x = np.linspace(0, L)
      ncolors = len(plt.rcParams['axes.prop_cycle'])
      shift = np.linspace(0, L, ncolors, endpoint=False)
      for s in shift:
          ax.plot(x, np.sin(x + s), 'o-')
  
  
  def image_and_patch_example(ax):
      ax.imshow(np.random.random(size=(20, 20)), interpolation='none')
      c = plt.Circle((5, 5), radius=5, label='patch')
      ax.add_patch(c)
  
  
  plt.style.use('grayscale')
  
  fig, (ax1, ax2) = plt.subplots(ncols=2)
  fig.suptitle("'grayscale' style sheet")
  
  color_cycle_example(ax1)
  image_and_patch_example(ax2)
  
  plt.show()
  