function [ n_data, x, fx ] = bessel_k0_int_values ( n_data )

%*****************************************************************************80
%
%% BESSEL_K0_INT_VALUES returns some values of the Bessel K0 integral.
%
%  Discussion:
%
%    The function is defined by:
%
%      K0_INT(x) = Integral ( 0 <= t <= x ) K0(t) dt
%
%    The data was reported by McLeod.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    29 August 2004
%
%  Author:
%
%    John Burkardt
%
%  Reference:
%
%    Allan McLeod,
%    Algorithm 757, MISCFUN: A software package to compute uncommon
%      special functions,
%    ACM Transactions on Mathematical Software,
%    Volume 22, Number 3, September 1996, pages 288-301.
%
%  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 = [ ...
     0.78587929563466784589E-02, ...
     0.26019991617330578111E-01, ...
     0.24311842237541167904E+00, ...
     0.39999633750480508861E+00, ...
     0.92710252093114907345E+00, ...
     0.12425098486237782662E+01, ...
     0.14736757343168286825E+01, ...
     0.15606495706051741364E+01, ...
     0.15673873907283660493E+01, ...
     0.15696345532693743714E+01, ...
     0.15701153443250786355E+01, ...
     0.15706574852894436220E+01, ...
     0.15707793116159788598E+01, ...
     0.15707942066465767196E+01, ...
     0.15707962315469192247E+01, ...
     0.15707963262340149876E+01, ...
     0.15707963267948756308E+01, ...
     0.15707963267948966192E+01, ...
     0.15707963267948966192E+01, ...
     0.15707963267948966192E+01  ];

  x_vec = [ ...
       0.0009765625E+00, ...
       0.0039062500E+00, ...
       0.0625000000E+00, ...
       0.1250000000E+00, ...
       0.5000000000E+00, ...
       1.0000000000E+00, ...
       2.0000000000E+00, ...
       4.0000000000E+00, ...
       5.0000000000E+00, ...
       6.0000000000E+00, ...
       6.5000000000E+00, ...
       8.0000000000E+00, ...
      10.0000000000E+00, ...
      12.0000000000E+00, ...
      15.0000000000E+00, ...
      20.0000000000E+00, ...
      30.0000000000E+00, ...
      50.0000000000E+00, ...
      80.0000000000E+00, ...
     100.0000000000E+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
