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

#*****************************************************************************80
#
## volcano_contour_fill() draws a filled contour plot of volcano (X,Y,Z) data.
#
#  Licensing:
#
#    This code is distributed under the MIT license.
#
#  Modified:
#
#    03 May 2019
#
#  Author:
#
#    John Burkardt
#
  import matplotlib.pyplot as plt
  import numpy as np
  from matplotlib import cm

  print ( '' )
  print ( 'volcano_contour_fill():' )
  print ( '  Make a filled contour plot Z(X,Y) of volcano elevation data.' )
#
#  Read the Z data from the file.
#
  zmat = np.loadtxt ( 'volcano_data.txt', dtype = 'f', delimiter = ' ' )
#
#  We have to create a grid of X and Y values corresponding to Z.
#
  m, n = zmat.shape
  print ( '  Z data has %d rows and %d columns' % ( m, n ) )
  xvec = np.linspace ( 0, n, n )
  yvec = np.linspace ( 0, m, m )
  xmat, ymat = np.meshgrid ( xvec, yvec )  
#
#  Form the figure.
#
  levels = 15
  plt.contourf ( xmat, ymat, zmat, levels, cmap = cm.coolwarm )
  plt.title ( 'Filled contour plot of Volcano', fontsize = 16 )
  plt.xlabel ( '<--- X --->', fontsize = 16 )
  plt.ylabel ( '<--- Y --->', fontsize = 16 )
  filename = 'volcano_contour_fill.png'
  plt.savefig ( filename )
  print ( '  Graphics saved as "%s"' % ( filename ) )
  plt.show ( )
  plt.close ( )

  return

def volcano_contour_line ( ):

#*****************************************************************************80
#
## volcano_contour_line() draws a contour line plot of volcano (X,Y,Z) data.
#
#  Licensing:
#
#    This code is distributed under the MIT license.
#
#  Modified:
#
#    03 May 2019
#
#  Author:
#
#    John Burkardt
#
  import matplotlib.pyplot as plt
  import numpy as np
  from matplotlib import cm

  print ( '' )
  print ( 'volcano_contour_line():' )
  print ( '  Make a contour line plot Z(X,Y) of volcano elevation data.' )
#
#  Read the Z data from the file.
#
  zmat = np.loadtxt ( 'volcano_data.txt', dtype = 'f', delimiter = ' ' )
#
#  We have to create a grid of X and Y values corresponding to Z.
#
  m, n = zmat.shape
  print ( '  Z data has %d rows and %d columns' % ( m, n ) )
  xvec = np.linspace ( 0, n - 1, n )
  yvec = np.linspace ( 0, m - 1, m )
  xmat, ymat = np.meshgrid ( xvec, yvec )  
#
#  Form the figure.
#
  levels = 15
  plt.contour ( xmat, ymat, zmat, levels, cmap = cm.coolwarm )
  plt.title ( 'Contour line plot of Volcano', fontsize = 16 )
  plt.xlabel ( '<--- X --->', fontsize = 16 )
  plt.ylabel ( '<--- Y --->', fontsize = 16 )
  filename = 'volcano_contour_line.png'
  plt.savefig ( filename )
  print ( '  Graphics saved as "%s"' % ( filename ) )
  plt.show ( )
  plt.close ( )

  return

def volcano_contour_both ( ):

#*****************************************************************************80
#
## volcano_contour_both() draws a filled and lined contour plot of volcano (X,Y,Z) data.
#
#  Licensing:
#
#    This code is distributed under the MIT license.
#
#  Modified:
#
#    28 February 2023
#
#  Author:
#
#    John Burkardt
#
  import matplotlib.pyplot as plt
  import numpy as np
  from matplotlib import cm

  print ( '' )
  print ( 'volcano_contour_both():' )
  print ( '  Make a filled contour plot Z(X,Y) of volcano elevation data.' )
#
#  Read the Z data from the file.
#
  zmat = np.loadtxt ( 'volcano_data.txt', dtype = 'f', delimiter = ' ' )
#
#  We have to create a grid of X and Y values corresponding to Z.
#
  m, n = zmat.shape
  print ( '  Z data has %d rows and %d columns' % ( m, n ) )
  xvec = np.linspace ( 0, n, n )
  yvec = np.linspace ( 0, m, m )
  xmat, ymat = np.meshgrid ( xvec, yvec )  
#
#  Form the figure.
#
  levels = 15
  plt.contourf ( xmat, ymat, zmat, levels, cmap = cm.coolwarm )
  plt.contour ( xmat, ymat, zmat, levels, colors = 'black' )
  plt.title ( 'Filled and lined contour plot of Volcano', fontsize = 16 )
  plt.xlabel ( '<--- X --->', fontsize = 16 )
  plt.ylabel ( '<--- Y --->', fontsize = 16 )
  filename = 'volcano_contour_both.png'
  plt.savefig ( filename )
  print ( '  Graphics saved as "%s"' % ( filename ) )
  plt.show ( )
  plt.close ( )

  return

if ( __name__ == '__main__' ):
  volcano_contour_line ( )
  volcano_contour_fill ( )
  volcano_contour_both ( )