text: """An example of reading topographical data from a file and displaying it."""
  
  import pandas as pd
  import matplotlib.pyplot as plt
  
  
  topo_file = "../../data/boulder-topography.asc"
  
  
  def read():
      try:
          topo = pd.read_csv(topo_file, header=None)
      except IOError:
          print("IOError: file '{}' cannot be read".format(topo_file))
      else:
          return topo
  
  
  def display(data, show=False, outfile="boulder_dem.png"):
      fig, ax = plt.subplots()
      elev = ax.imshow(data, cmap="viridis")
      fig.colorbar(elev, label="Elevation (m)")
      plt.title("Boulder Topography")
  
      if show is True:
          plt.show()
      else:
          plt.savefig(outfile, dpi=96)
          plt.close()
  
  
  if __name__ == "__main__":
      topo = read()
      if topo is not None:
          display(topo)
  