| /* |
| * 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 |
| * |
| * Random variates from the Weibull distribution. |
| */ |
| |
| #include "nmath.h" |
| |
| double rweibull(double shape, double scale) |
| { |
| if (!R_FINITE(shape) || !R_FINITE(scale) || shape <= 0. || scale <= 0.) { |
| if(scale == 0.) return 0.; |
| /* else */ |
| ML_ERR_return_NAN; |
| } |
| |
| return scale * pow(-log(unif_rand()), 1.0 / shape); |
| } |