code: def main():
      # Test data
      x, y = np.mgrid[-5:5:0.05, -5:5:0.05]
      z = 5 * (np.sqrt(x**2 + y**2) + np.sin(x**2 + y**2))
  
      dem = cbook.get_sample_data("jacksboro_fault_dem.npz")
      elev = dem["elevation"]
  
      fig = compare(z, plt.cm.copper)
      fig.suptitle(
          "HSV Blending Looks Best with Smooth Surfaces", y=0.95
      )
  
      fig = compare(elev, plt.cm.gist_earth, ve=0.05)
      fig.suptitle(
          "Overlay Blending Looks Best with Rough Surfaces", y=0.95
      )
  
      plt.show()
  
imports: import matplotlib.pyplot
  import numpy
  from matplotlib import cbook
  from matplotlib.colors import LightSource
label_desc: Use image node_id 1 for calling a global function with example usage: main() without return types