#! /usr/bin/env python
#
def pyramid01_sample ( n, seed ):

#*****************************************************************************80
#
## PYRAMID01_SAMPLE: sample the unit pyramid.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    22 June 2015
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Input, integer N, the number of samples desired.
#
#    Input/output, integer SEED, a seed for the random
#    number generator.
#
#    Output, real X(3,N), the sample values.
#
  from r8mat_uniform_01 import r8mat_uniform_01

  one_third = 1.0 / 3.0

  x, seed = r8mat_uniform_01 ( 3, n, seed )

  for j in range ( 0, n ):
    x[2,j] = 1.0 - x[2,j] ** one_third
    x[1,j] = ( 1.0 - x[2,j] ) * ( 2.0 * x[1,j] - 1.0 )
    x[0,j] = ( 1.0 - x[2,j] ) * ( 2.0 * x[0,j] - 1.0 )

  return x, seed

def pyramid01_sample_test ( ):

#*****************************************************************************80
#
## PYRAMID01_SAMPLE_TEST tests PYRAMID01_SAMPLE.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    22 June 2015
#
#  Author:
#
#    John Burkardt
#
  import platform
  from r8mat_transpose_print import r8mat_transpose_print

  print ( '' )
  print ( 'PYRAMID01_SAMPLE_TEST' )
  print ( '  Python version: %s' % ( platform.python_version ( ) ) )
  print ( '  PYRAMID01_SAMPLE samples points from the unit pyramid.' )

  n = 20
  seed = 123456789
  x, seed = pyramid01_sample ( n, seed )

  m = 3
  r8mat_transpose_print ( m, n, x, '  Unit pyramid points' )
#
#  Terminate.
#
  print ( '' )
  print ( 'PYRAMID01_SAMPLE_TEST' )
  print ( '  Normal end of execution.' )
  return

if ( __name__ == '__main__' ):
  from timestamp import timestamp
  timestamp ( )
  pyramid01_sample_test ( )
  timestamp ( )