function [ n_data, a, b, x, fx ] =  hyper_1f1_values ( n_data )

%*****************************************************************************80
%
%% HYPER_1F1_VALUES returns some values of the hypergeometric function 1F1.
%
%  Discussion:
%
%    In Mathematica, the function can be evaluated by:
%
%      fx = Hypergeometric1F1 [ a, b, x ]
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license. 
%
%  Modified:
%
%    28 March 2010
%
%  Author:
%
%    John Burkardt
%
%  Reference:
%
%    Milton Abramowitz, Irene Stegun,
%    Handbook of Mathematical Functions,
%    National Bureau of Standards, 1964,
%    ISBN: 0-486-61272-4,
%    LC: QA47.A34.
%
%    Stephen Wolfram,
%    The Mathematica Book,
%    Fourth Edition,
%    Cambridge University Press, 1999,
%    ISBN: 0-521-64314-7,
%    LC: QA76.95.W65.
%
%    Daniel Zwillinger, editor,
%    CRC Standard Mathematical Tables and Formulae,
%    30th Edition,
%    CRC Press, 1996,
%    ISBN: 0-8493-2479-3,
%    LC: QA47.M315.
%
%  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 A, B, X, the parameters.
%
%    Output, real FX, the value of the function.
%
  n_max = 24;

  a_vec = [ ...
    -2.500, ...
    -0.500, ...
     0.500, ...
     2.500, ...
    -2.500, ...
    -0.500, ...
     0.500, ...
     2.500, ...
    -2.500, ...
    -0.500, ...
     0.500, ...
     2.500, ...
     0.825, ...
     1.100, ...
     1.650, ...
     3.300, ...
     0.825, ...
     1.100, ...
     1.650, ...
     3.300, ...
     0.825, ...
     1.100, ...
     1.650,... 
     3.300 ];
  b_vec = [ ...
     3.3, ...
     1.1, ...
     1.1, ...
     3.3, ...
     3.3, ...
     1.1, ...
     1.1, ...
     3.3, ...
     3.3, ...
     1.1, ...
     1.1, ...
     3.3, ...
     6.7, ...
     6.7, ...
     6.7, ...
     6.7, ...
     6.7, ...
     6.7, ...
     6.7, ...
     6.7, ...
     6.7, ...
     6.7, ...
     6.7, ...
     6.7 ];
  fx_vec = [ ...
     0.81879926689265186854, ...
     0.88283984828032972070, ...
     1.1245023764952626690, ...
     1.2101049301639599598, ...
     0.12723045536781567174, ...
     0.12326016871544045107, ...
     2.3297954665128293051, ...
     3.3890020264468009733, ...
    -0.18819510282516768874, ...
    -1.0764203806547022727, ...
     5.7521824680907968433, ...
     9.9998567403304086593, ...
     1.0317208964319891384, ...
     1.0424867029249952040, ...
     1.0643112000949092012, ...
     1.1321844369742336326, ...
     1.2328402688568452181, ...
     1.3200654482027340732, ...
     1.5104811522310825217, ...
     2.2307520785940524365, ...
     1.5197286298183137741, ...
     1.7364938170250847619, ...
     2.2492330307668135926, ...
     4.6377737119178965298 ];
  x_vec = [ ...
     0.25, ...
     0.25, ...
     0.25, ...
     0.25, ...
     1.55, ...
     1.55, ...
     1.55, ...
     1.55, ...
     2.85, ...
     2.85, ...
     2.85, ...
     2.85, ...
     0.25, ...
     0.25, ...
     0.25, ...
     0.25, ...
     1.55, ...
     1.55, ...
     1.55, ...
     1.55, ...
     2.85, ...
     2.85, ...
     2.85, ...
     2.85 ];

  if ( n_data < 0 )
    n_data = 0;
  end
 
  n_data = n_data + 1;

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

  return
end
