function [ n_data, x, fx ] = exp_values ( n_data )
%*****************************************************************************80
%
%% EXP_VALUES returns some values of the exponential function.
%
% Discussion:
%
% In Mathematica, the function can be evaluated by:
%
% Exp[x]
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 18 June 2007
%
% 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.
%
% 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 = 19;
fx_vec = [ ...
0.000045399929762484851536E+00, ...
0.0067379469990854670966E+00, ...
0.36787944117144232160E+00, ...
1.0000000000000000000E+00, ...
1.1051709180756476248E+00, ...
1.2214027581601698339E+00, ...
1.3498588075760031040E+00, ...
1.4918246976412703178E+00, ...
1.6487212707001281468E+00, ...
1.8221188003905089749E+00, ...
2.0137527074704765216E+00, ...
2.2255409284924676046E+00, ...
2.4596031111569496638E+00, ...
2.7182818284590452354E+00, ...
7.3890560989306502272E+00, ...
23.140692632779269006E+00, ...
148.41315910257660342E+00, ...
22026.465794806716517E+00, ...
4.8516519540979027797E+08 ];
x_vec = [ ...
-10.0E+00, ...
-5.0E+00, ...
-1.0E+00, ...
0.0E+00, ...
0.1E+00, ...
0.2E+00, ...
0.3E+00, ...
0.4E+00, ...
0.5E+00, ...
0.6E+00, ...
0.7E+00, ...
0.8E+00, ...
0.9E+00, ...
1.0E+00, ...
2.0E+00, ...
3.1415926535897932385E+00, ...
5.0E+00, ...
10.0E+00, ...
20.0E+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
