function x = f_sample ( m, n )

%*****************************************************************************80
%
%% f_sample() samples the F central PDF.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    30 October 2004
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    integer M, N, the parameters of the PDF.
%    1 <= M,
%    1 <= N.
%
%  Output:
%
%    real X, a sample of the PDF.
%
  xm = chi_square_sample ( m );
  xn = chi_square_sample ( n );

  x = n * xm / ( m * xn );

  return
end
