1 /*
2 * Mathlib : A C Library of Special Functions
3 * Copyright (C) 1998 Ross Ihaka
4 * Copyright (C) 2000-8 The R Core Team
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, a copy is available at
18 * http://www.r-project.org/Licenses/
19 *
20 * DESCRIPTION
21 *
22 * The lognormal distribution function.
23 */
24
25 #include "nmath.h"
26 #include "dpq.h"
27
plnorm(double x,double meanlog,double sdlog,int lower_tail,int log_p)28 double plnorm(double x, double meanlog, double sdlog, int lower_tail, int log_p)
29 {
30 #ifdef IEEE_754
31 if (ISNAN(x) || ISNAN(meanlog) || ISNAN(sdlog))
32 return x + meanlog + sdlog;
33 #endif
34 if (sdlog <= 0) ML_ERR_return_NAN;
35
36 if (x > 0)
37 return pnorm(log(x), meanlog, sdlog, lower_tail, log_p);
38 return R_DT_0;
39 }
40