1/* specfunc/gsl_sf_lambert.h
2 *
3 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001 Gerard Jungman
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 3 of the License, or (at
8 * your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 */
19
20/* Author: G. Jungman */
21
22#ifndef __GSL_SF_LAMBERT_H__
23#define __GSL_SF_LAMBERT_H__
24
25#include <gsl/gsl_sf_result.h>
26
27#undef __BEGIN_DECLS
28#undef __END_DECLS
29#ifdef __cplusplus
30# define __BEGIN_DECLS extern "C" {
31# define __END_DECLS }
32#else
33# define __BEGIN_DECLS /* empty */
34# define __END_DECLS /* empty */
35#endif
36
37__BEGIN_DECLS
38
39
40/* Lambert's Function W_0(x)
41 *
42 * W_0(x) is the principal branch of the
43 * implicit function defined by W e^W = x.
44 *
45 * -1/E < x < \infty
46 *
47 * exceptions: GSL_EMAXITER;
48 */
49int gsl_sf_lambert_W0_e(double x, gsl_sf_result * result);
50double gsl_sf_lambert_W0(double x);
51
52
53/* Lambert's Function W_{-1}(x)
54 *
55 * W_{-1}(x) is the second real branch of the
56 * implicit function defined by W e^W = x.
57 * It agrees with W_0(x) when x >= 0.
58 *
59 * -1/E < x < \infty
60 *
61 * exceptions: GSL_MAXITER;
62 */
63int gsl_sf_lambert_Wm1_e(double x, gsl_sf_result * result);
64double gsl_sf_lambert_Wm1(double x);
65
66
67__END_DECLS
68
69#endif /* __GSL_SF_LAMBERT_H__ */
70