#! /usr/bin/env python3
#
def i18_points ( ):

  import matplotlib.pyplot as plt
  import numpy as np

  print ( '' )
  print ( 'i18_points():' )
  print ( '  Display 18 points for geometry exercise.' )

  points = np.loadtxt ( 'i18.txt' )
#
#  Display just the points.
#
  plt.clf ( )
  plt.plot ( points[:,0], points[:,1], 'o' )
  for i in range ( 0, points.shape[0] ):
    plt.text ( points[i,0], points[i,1], str(i), fontsize = 15 )
  plt.grid ( 'True' )
  filename = 'i18_points.png'
  plt.savefig ( filename )
  print ( '  Graphics saved as "' + filename + '"' )
  plt.show ( )
  plt.close ( )

  return

if ( __name__ == "__main__" ):
  i18_points ( )