#! /usr/bin/env python3
#
def wedge01_sample ( n, seed ):

#*****************************************************************************80
#
## WEDGE01_SAMPLE samples points uniformly from the unit wedge in 3D.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license. 
#
#  Modified:
#
#    23 June 2015
#
#  Author:
#
#    John Burkardt
#
#  Reference:
#
#    Reuven Rubinstein,
#    Monte Carlo Optimization, Simulation, and Sensitivity 
#    of Queueing Networks,
#    Krieger, 1992,
#    ISBN: 0894647644,
#    LC: QA298.R79.
#
#  Parameters:
#
#    Input, integer N, the number of points.
#
#    Input/output, integer SEED, a seed for the random 
#    number generator.
#
#    Output, real X(3,N), the points.
#
  import numpy as np
  from r8vec_uniform_01 import r8vec_uniform_01

  m = 3

  x = np.zeros ( [ m, n ] )

  for j in range ( 0, n ):

    e, seed = r8vec_uniform_01 ( m + 1, seed );

    el = np.zeros ( m )

    el_sum = 0.0
    for i in range ( 0, m ):
      el[i] = - np.log ( e[i] )
      el_sum = el_sum + el[i]

    x[0,j] = el[0] / el_sum
    x[1,j] = el[1] / el_sum
    x[2,j] = 2.0 * e[3] - 1.0

  return x, seed

def wedge01_sample_test ( ):

#*****************************************************************************80
#
## WEDGE01_SAMPLE_TEST tests WEDGE01_SAMPLE.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    23 June 2015
#
#  Author:
#
#    John Burkardt
#
  import platform
  from r8mat_transpose_print import r8mat_transpose_print

  print ( '' )
  print ( 'WEDGE01_SAMPLE_TEST' )
  print ( '  Python version: %s' % ( platform.python_version ( ) ) )
  print ( '  WEDGE01_SAMPLE samples the unit wedge.' )

  m = 3
  n = 10
  seed = 123456789

  x, seed = wedge01_sample ( n, seed )

  r8mat_transpose_print ( m, n, x, '  Sample points in the unit wedge.' )
#
#  Terminate.
#
  print ( '' )
  print ( 'WEDGE01_SAMPLE_TEST' )
  print ( '  Normal end of execution.' )
  return

if ( __name__ == '__main__' ):
  from timestamp import timestamp
  timestamp ( )
  wedge01_sample_test ( )
  timestamp ( )