#! /usr/bin/env python
#
def beta_log_values ( n_data ):

#*****************************************************************************80
#
## BETA_LOG_VALUES returns some values of the logarithm of the Beta function.
#
#  Discussion:
#
#    In Mathematica, the function can be evaluated by:
#
#      Log[Beta[x]]
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    15 January 2015
#
#  Author:
#
#    John Burkardt
#
#  Reference:
#
#    Milton Abramowitz and Irene Stegun,
#    Handbook of Mathematical Functions,
#    US Department of Commerce, 1964.
#
#    Stephen Wolfram,
#    The Mathematica Book,
#    Fourth Edition,
#    Wolfram Media / Cambridge University Press, 1999.
#
#  Parameters:
#
#    Input/output, integer N_DATA.  The user sets N_DATA to 0 before the
#    first call.  On each call, the routine increments N_DATA by 1, and
#    returns the corresponding data; when there is no more data, the
#    output value of N_DATA will be 0 again.
#
#    Output, real X, Y, the arguments of the function.
#
#    Output, real FXY, the value of the function.
#
  import numpy as np

  n_max = 17

  f_vec = np.array ( ( \
      0.1609437912434100E+01, \
      0.9162907318741551E+00, \
      0.5108256237659907E+00, \
      0.2231435513142098E+00, \
      0.1609437912434100E+01, \
      0.9162907318741551E+00, \
      0.0000000000000000E+00, \
     -0.1791759469228055E+01, \
     -0.3401197381662155E+01, \
     -0.4941642422609304E+01, \
     -0.6445719819385578E+01, \
     -0.3737669618283368E+01, \
     -0.5123963979403259E+01, \
     -0.6222576268071369E+01, \
     -0.7138866999945524E+01, \
     -0.7927324360309794E+01, \
     -0.9393661429103221E+01 ) )

  x_vec = np.array ( ( \
     0.2E+00, \
     0.4E+00, \
     0.6E+00, \
     0.8E+00, \
     1.0E+00, \
     1.0E+00, \
     1.0E+00, \
     2.0E+00, \
     3.0E+00, \
     4.0E+00, \
     5.0E+00, \
     6.0E+00, \
     6.0E+00, \
     6.0E+00, \
     6.0E+00, \
     6.0E+00, \
     7.0E+00  ) )

  y_vec = np.array ( ( \
     1.0E+00, \
     1.0E+00, \
     1.0E+00, \
     1.0E+00, \
     0.2E+00, \
     0.4E+00, \
     1.0E+00, \
     2.0E+00, \
     3.0E+00, \
     4.0E+00, \
     5.0E+00, \
     2.0E+00, \
     3.0E+00, \
     4.0E+00, \
     5.0E+00, \
     6.0E+00, \
     7.0E+00   ) )

  if ( n_data < 0 ):
    n_data = 0

  if ( n_max <= n_data ):
    n_data = 0
    x = 0.0
    y = 0.0
    f = 0.0
  else:
    x = x_vec[n_data]
    y = y_vec[n_data]
    f = f_vec[n_data]
    n_data = n_data + 1

  return n_data, x, y, f

def beta_log_values_test ( ):

#*****************************************************************************80
#
## BETA_LOG_VALUES_TEST demonstrates the use of BETA_LOG_VALUES.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    15 January 2015
#
#  Author:
#
#    John Burkardt
#
  print ( '' )
  print ( 'BETA_LOG_VALUES_TEST:' )
  print ( '  BETA_LOG_VALUES stores values of the Log(BETA) function.' )
  print ( '' )
  print ( '      X         Y         Log(BETA(X,Y))' )
  print ( '' )

  n_data = 0

  while ( True ):

    n_data, x, y, f = beta_log_values ( n_data )

    if ( n_data == 0 ):
      break

    print ( '  %12f  %12f  %24.16g' % ( x, y, f ) )
#
#  Terminate.
#
  print ( '' )
  print ( 'BETA_LOG_VALUES_TEST:' )
  print ( '  Normal end of execution.' )
  return

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