| /* |
| * 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/ |
| * |
| * SYNOPSIS |
| * |
| * #include "mathlib.h" |
| * double rf(double dfn, double dfd); |
| * |
| * DESCRIPTION |
| * |
| * Pseudo-random variates from an F distribution. |
| * |
| * NOTES |
| * |
| * This function calls rchisq to do the real work |
| */ |
| |
| #include "nmath.h" |
| |
| double rf(double n1, double n2) |
| { |
| double v1, v2; |
| if (ISNAN(n1) || ISNAN(n2) || n1 <= 0. || n2 <= 0.) |
| ML_ERR_return_NAN; |
| |
| v1 = R_FINITE(n1) ? (rchisq(n1) / n1) : 1; |
| v2 = R_FINITE(n2) ? (rchisq(n2) / n2) : 1; |
| return v1 / v2; |
| } |