#! /usr/bin/env python3
#
def temperature_scatter3d ( ):

#*****************************************************************************80
#
## temperature_scatter3d() creates a 3D scatter plot of temperature.
#
#  Licensing:
#
#    This code is distributed under the MIT license.
#
#  Modified:
#
#    02 October 2026
#
#  Author:
#
#    John Burkardt
#
  import matplotlib
  import numpy as np
  import platform

  print ( '' )
  print ( 'temperature_scatter3d():' )
  print ( '  matplotlib version: ' + matplotlib.__version__ )
  print ( '  numpy version:      ' + np.version.version )
  print ( '  python version:     ' + platform.python_version ( ) )
  print ( '  Create a 3D scatter plot of' )
  print ( '  January temperatures across the US.')
#
#  Define file names.
#
  command_filename = "temperature_commands.txt"
  data_filename = "temperature_data.txt"
  plot_filename = "temperature_scatter3d.png"
#
#  Create the command file.
#
  command_unit = open ( command_filename, 'wt' )
  command_unit.write ( '# ' + command_filename + '\n' )
  command_unit.write ( '#\n' )
  command_unit.write ( '# Usage:\n' )
  command_unit.write ( '#  gnuplot < ' + command_filename + '\n' )
  command_unit.write ( '#\n' )
  command_unit.write ( 'set term png\n' )
  command_unit.write ( 'set output "' + plot_filename + '"\n' )
  command_unit.write ( 'set xlabel "<--- Longitude --->"\n' )
  command_unit.write ( 'set ylabel "<--- Latitude --->"\n' )
  command_unit.write ( 'set zlabel "<--- Temperature --->"\n' )
  command_unit.write ( 'set title "January temperatures across US"\n' )
  command_unit.write ( 'set grid\n' )
  command_unit.write ( 'set timestamp\n' )
  command_unit.write ( 'set view equal xyz\n' )
  command_unit.write ( 'unset key\n' )
  command_unit.write ( "splot '" + data_filename \
    + "' using 2:3:1 with points pt 7 ps 2\n" )
  command_unit.write ( 'quit\n' )
  command_unit.close ( )
  print ( '  Created command file "' + command_filename + '"' )

  return

def timestamp ( ):

#*****************************************************************************80
#
## timestamp() prints the date as a timestamp.
#
#  Licensing:
#
#    This code is distributed under the MIT license. 
#
#  Modified:
#
#    21 August 2019
#
#  Author:
#
#    John Burkardt
#
  import time

  t = time.time ( )
  print ( time.ctime ( t ) )

  return

if ( __name__ == '__main__' ):
  timestamp ( )
  temperature_scatter3d ( )
  timestamp ( )