function x = normal_truncated_ab_sample ( mu, s, a, b )

%*****************************************************************************80
%
%% normal_truncated_ab_sample() samples the truncated Normal PDF.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    14 August 2013
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real MU, S, the mean and standard deviation of the
%    parent Normal distribution.
%
%    real A, B, the lower and upper truncation limits.
%
%  Output:
%
%    real X, a sample of the PDF.
%
  alpha = ( a - mu ) / s;
  beta = ( b - mu ) / s;

  alpha_cdf = normal_01_cdf ( alpha );
  beta_cdf = normal_01_cdf ( beta );

  u = rand ( 1, 1 );
  xi_cdf = alpha_cdf + u * ( beta_cdf - alpha_cdf );
  xi = normal_01_cdf_inv ( xi_cdf );

  x = mu + s * xi;

  return
end
