def california_migration_matrix_test ( ):

#*****************************************************************************80
#
## california_migration_matrix_test() tests california_migration_matrix().
#
#  Licensing:
#
#    This code is distributed under the MIT license.
#
#  Modified:
#
#    19 January 2025
#
#  Author:
#
#    John Burkardt
#
  import matplotlib.pyplot as plt
  import numpy as np

  print ( '' )
  print ( 'california_migration_matrix_test():' )
  print ( '  Test california_migration_matrix().' )

  A = np.array ( [ \
    [ 0.70, 0.10 ], \
    [ 0.30, 0.90 ] ] )

  print ( '' )
  print ( '  Year     CA Pop     US pop      Total' )
  print ( '' )

  m = 21
  pop = np.zeros ( [ m, 2 ] )
  year = np.linspace ( 1960, 1960 + m - 1, m )

  for i in range ( 0, m ):

    if ( i == 0 ):
      pop[0,0] =  16000000
      pop[0,1] = 164000000
    else:
      pop[i,0:2] = np.matmul ( A, pop[i-1,0:2] )

    print ( '  %4d  %9.0f  %9.0f  %9.0f' \
      % ( year[i], pop[i,0], pop[i,1], pop[i,0] + pop[i,1] ) )

  plt.clf ( )
  plt.plot ( year, pop[:,0], linewidth = 3 )
  plt.plot ( year, pop[:,1], linewidth = 3 )
  plt.grid ( True )
  plt.xlabel ( '<-- Year -->' )
  plt.ylabel ( '<-- Population -->' )
  plt.title ( 'California population matrix' )
  plt.legend ( [ 'CA', 'US' ] )
  filename = 'california_migration_matrix.png'
  plt.savefig ( filename )     
  print ( '  Graphics saved as "' + filename + '"' )
  plt.close ( )

  return

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