function [ n_data, x, fx ] = bessel_y1_spherical_values ( n_data )

%*****************************************************************************80
%
%% BESSEL_Y1_SPHERICAL_VALUES returns some values of the Spherical Bessel function y1.
%
%  Discussion:
%
%    In Mathematica, the function can be evaluated by:
%
%      Sqrt[Pi/(2*x)] * BesselY[3/2,x]
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    22 August 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 = 21;

  fx_vec = [ ...
     -0.1004987506942709E+03, ...
     -0.2549501110000635E+02, ...
     -0.6730177068289658E+01, ...
     -0.3233669719296388E+01, ...
     -0.1985299346979349E+01, ...
     -0.1381773290676036E+01, ...
     -0.1028336567803712E+01, ...
     -0.7906105943286149E+00, ...
     -0.6133274385019998E+00, ...
     -0.4709023582986618E+00, ...
     -0.3506120042760553E+00, ...
     -0.2459072254437506E+00, ...
     -0.1534232496148467E+00, ...
     -0.7151106706610352E-01, ...
      0.5427959479750482E-03, ...
      0.6295916360231598E-01, ...
      0.1157316440198251E+00, ...
      0.1587922092967723E+00, ...
      0.1921166676076864E+00, ...
      0.2157913917934037E+00, ...
      0.2300533501309578E+00 ];

  x_vec = [ ...
     0.1E+00, ...
     0.2E+00, ...
     0.4E+00, ...
     0.6E+00, ...
     0.8E+00, ...
     1.0E+00, ...
     1.2E+00, ...
     1.4E+00, ...
     1.6E+00, ...
     1.8E+00, ...
     2.0E+00, ...
     2.2E+00, ...
     2.4E+00, ...
     2.6E+00, ...
     2.8E+00, ...
     3.0E+00, ...
     3.2E+00, ...
     3.4E+00, ...
     3.6E+00, ...
     3.8E+00, ...
     4.0E+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
