/*

 *  Mathlib : A C Library of Special Functions

 *  Copyright (C) 1998  Ross Ihaka

 *  Copyright (C) 2000  The R Core Team

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful, but

 *  WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 *  General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, a copy is available at

 *  https://www.R-project.org/Licenses/

 *

 *  DESCRIPTION

 *

 *     The distribution function of the chi-squared distribution.

 */

#include "nmath.h"

#include "dpq.h"

double pchisq(double x, double df, int lower_tail, int log_p)

{

    return pgamma(x, df/2., 2., lower_tail, log_p);

}