#! /usr/bin/env python
#
def get_seed ( ):

#*****************************************************************************80
#
## GET_SEED returns a random seed for the random number generator.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license. 
#
#  Modified:
#
#    07 April 2013
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Output, integer SEED, a random seed value.
#
  import time
#
#  Get a floating point number, measured in seconds,
#  that represents the elapsed time since the epoch.
#
  seed = time.time ( )
#
#  Reduce the number to an integer.
#
  seed = int ( seed )
#
#  Use modulo arithmetic to get an integer between 1 and I4_HUGE.
#
  i4_huge = 2147483647
  seed = ( seed % i4_huge ) + 1

  return seed

def get_seed_test ( ):

#*****************************************************************************80
#
## GET_SEED_TEST tests GET_SEED.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license. 
#
#  Modified:
#
#    07 April 2013
#
#  Author:
#
#    John Burkardt
#
  import platform
  from r8_uniform_01 import r8_uniform_01

  print ( '' )
  print ( 'GET_SEED_TEST' )
  print ( '  Python version: %s' % ( platform.python_version ( ) ) )
  print ( '  GET_SEED picks an initial seed value for R8_UNIFORM_01.' )
  print ( '  The value chosen should vary over time, because' )
  print ( '  the seed is based on reading the clock.' )
  print ( '' )
  print ( '  This is just the "calendar" clock, which does' )
  print ( '  not change very fast, so calling GET_SEED several' )
  print ( '  times in a row may result in the same value.' )

  seed = 12345678
  seed_old = seed

  print ( '' )
  print ( '  Initial seed is %d' % ( seed ) )
  print ( '' )
  print ( '  Next 3 values of R8_UNIFORM_01:' )
  print ( '' )

  for j in range ( 0, 3 ):
    [ r, seed ] = r8_uniform_01 ( seed )
    print ( '  %f' % ( r ) )

  for i in range ( 0, 4 ):

    while ( True ):

      seed = get_seed ( )

      if ( seed != seed_old ):
        seed_old = seed
        break

    print ( '' )
    print ( '  New seed from GET_SEED is = %d' % ( seed ) )
    print ( '' )
    print ( '  Next 3 values of R8_UNIFORM_01:' )
    print ( '' )

    for j in range ( 0, 3 ):
      [ r, seed ] = r8_uniform_01 ( seed )
      print ( '  %f' % ( r ) )
#
#  Terminate.
#
  print ( '' )
  print ( 'GET_SEED_TEST:' )
  print ( '  Normal end of execution.' )
  return

if ( __name__ == '__main__' ):
  from timestamp import timestamp
  timestamp ( )
  get_seed_test ( )
  timestamp ( )