function [ n_data, x, fx ] = gamma_log_values ( n_data )

%% GAMMA_LOG_VALUES returns some values of the Log Gamma function.
%
%  Discussion:
%
%    In Mathematica, the function can be evaluated by:
%
%      Log[Gamma[x]]
%
%  Modified:
%
%    16 September 2004
%
%  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, the argument of the function.
%
%    Output, real FX, the value of the function.
%
  n_max = 20;

  fx_vec = [ ...
      0.1524063822430784E+01, ...
      0.7966778177017837E+00, ...
      0.3982338580692348E+00, ...
      0.1520596783998375E+00, ...
      0.0000000000000000E+00, ...
     -0.4987244125983972E-01, ...
     -0.8537409000331584E-01, ...
     -0.1081748095078604E+00, ...
     -0.1196129141723712E+00, ...
     -0.1207822376352452E+00, ...
     -0.1125917656967557E+00, ...
     -0.9580769740706586E-01, ...
     -0.7108387291437216E-01, ...
     -0.3898427592308333E-01, ...
     0.00000000000000000E+00, ...
     0.69314718055994530E+00, ...
     0.17917594692280550E+01, ...
     0.12801827480081469E+02, ...
     0.39339884187199494E+02, ...
     0.71257038967168009E+02 ]; 

  x_vec = [ ...
      0.20E+00, ...
      0.40E+00, ...
      0.60E+00, ...
      0.80E+00, ...
      1.00E+00, ...
      1.10E+00, ...
      1.20E+00, ...
      1.30E+00, ...
      1.40E+00, ...
      1.50E+00, ...
      1.60E+00, ...
      1.70E+00, ...
      1.80E+00, ...
      1.90E+00, ...
      2.00E+00, ...
      3.00E+00, ...
      4.00E+00, ...
     10.00E+00, ...
     20.00E+00, ...
     30.00E+00 ]; 

  if ( n_data < 0 )
    n_data = 0;
  end

  n_data = n_data + 1;

  if ( n_max < n_data )
    n_data = 0;
    x = 0.0;
    fx = 0.0;
  else
    x = x_vec(n_data);
    fx = fx_vec(n_data);
  end

  return
end