/* * 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 quantile function of the chi-squared distribution. */ #include "nmath.h" #include "dpq.h" double qchisq(double p, double df, int lower_tail, int log_p) { return qgamma(p, 0.5 * df, 2.0, lower_tail, log_p); }