| /* |
| * Mathlib : A C Library of Special Functions |
| * Copyright (C) 1998 Ross Ihaka |
| * Copyright (C) 2000-2015 The R Core Team |
| * Copyright (C) 2004-2015 The R Foundation |
| * |
| * 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 binomial distribution. |
| */ |
| #include "nmath.h" |
| #include "dpq.h" |
| |
| double pbinom(double x, double n, double p, int lower_tail, int log_p) |
| { |
| #ifdef IEEE_754 |
| if (ISNAN(x) || ISNAN(n) || ISNAN(p)) |
| return x + n + p; |
| if (!R_FINITE(n) || !R_FINITE(p)) ML_ERR_return_NAN; |
| |
| #endif |
| if(R_nonint(n)) { |
| MATHLIB_WARNING(_("non-integer n = %f"), n); |
| ML_ERR_return_NAN; |
| } |
| n = R_forceint(n); |
| /* PR#8560: n=0 is a valid value */ |
| if(n < 0 || p < 0 || p > 1) ML_ERR_return_NAN; |
| |
| if (x < 0) return R_DT_0; |
| x = floor(x + 1e-7); |
| if (n <= x) return R_DT_1; |
| return pbeta(p, x + 1, n - x, !lower_tail, log_p); |
| } |