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

#*****************************************************************************80
#
## faithful_both() analyzes, displays, and normalizes the data
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license. 
#
#  Modified:
#
#    27 September 2023
#
#  Author:
#
#    John Burkardt
#
  import numpy as np

  print ( '' )
  print ( 'faithful_both():' )
  print ( '  Initial analysis and display of Old Faithful data.' )
#
#  Read the data.
#
  data = np.loadtxt ( 'faithful_data.txt' )

  print ( '' )
  print ( '  Statistics for Old Faithful eruption and wait times' )
  print ( '  data.shape = ', data.shape )
  print ( '  data min   = ', np.min ( data, axis = 0 ) )
  print ( '  data mean  = ', np.mean ( data, axis = 0 ) )
  print ( '  data max   = ', np.max ( data, axis = 0 ) )
  print ( '  data var   = ', np.var ( data, axis = 0 ) )
  print ( '  data std   = ', np.std ( data, axis = 0 ) )
#
#  Create x and y.
#
  print ( '' )
  print ( '  Display raw data' )

  x = data[:,0]
  y = data[:,1]
  faithful_display ( x, y, 'faithful_raw.png' )

  print ( '' )
  print ( '  Display normalized data' )

  xn = ( x - np.min ( x ) ) / ( np.max ( x ) - np.min ( x ) )
  yn = ( y - np.min ( y ) ) / ( np.max ( y ) - np.min ( y ) )
  faithful_display ( xn, yn, 'faithful_normalized.png' )
  datan = np.column_stack ( [ xn, yn ] )
  np.savetxt ( 'faithful_normalized.txt', datan )

  print ( '' )
  print ( '  Display standardized data' )

  xs = ( x - np.mean ( x ) ) / np.std ( x )
  ys = ( y - np.mean ( y ) ) / np.std ( y )
  faithful_display ( xs, ys, 'faithful_standardized.png' )
  datas = np.column_stack ( [ xs, ys ] )
  np.savetxt ( 'faithful_standardized.txt', datas )
#
#  Terminate.
#
  print ( '' )
  print ( 'faithful_both():' )
  print ( '  Normal end of execution.' )

  return

def faithful_display ( x, y, filename ):

#*****************************************************************************80
#
## faithful_display() displays the Old Faithful data.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    21 January 2022
#
#  Author:
#
#    John Burkardt
#
  import matplotlib.pyplot as plt
  import numpy as np
  import platform

  plt.plot ( x, y, 'k.', markersize = 10 )
  plt.xlabel ( '<-- Erupt -->', fontsize = 16 )
  plt.ylabel ( '<-- Wait -->', fontsize = 16 )
  plt.title ( filename )
  plt.grid ( True )
  plt.axis ( 'equal' )
  plt.savefig ( filename )
  print ( '  Graphics saved as "%s"' % ( filename ) )
  plt.show ( )
  plt.clf ( )

  return

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