include/gsl/gsl_sf_lambert.h

0001 /* specfunc/gsl_sf_lambert.h
0002  *
0003  * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001 Gerard Jungman
0004  *
0005  * This program is free software; you can redistribute it and/or modify
0006  * it under the terms of the GNU General Public License as published by
0007  * the Free Software Foundation; either version 3 of the License, or (at
0008  * your option) any later version.
0009  *
0010  * This program is distributed in the hope that it will be useful, but
0011  * WITHOUT ANY WARRANTY; without even the implied warranty of
0012  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
0013  * General Public License for more details.
0014  *
0015  * You should have received a copy of the GNU General Public License
0016  * along with this program; if not, write to the Free Software
0017  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
0018  */
0019
0020 /* Author:  G. Jungman */
0021
0022 #ifndef __GSL_SF_LAMBERT_H__
0023 #define __GSL_SF_LAMBERT_H__
0024
0025 #include <gsl/gsl_sf_result.h>
0026
0027 #undef __BEGIN_DECLS
0028 #undef __END_DECLS
0029 #ifdef __cplusplus
0030 # define __BEGIN_DECLS extern "C" {
0031 # define __END_DECLS }
0032 #else
0033 # define __BEGIN_DECLS /* empty */
0034 # define __END_DECLS /* empty */
0035 #endif
0036
0037 __BEGIN_DECLS
0038
0039
0040 /* Lambert's Function W_0(x)
0041  *
0042  * W_0(x) is the principal branch of the
0043  * implicit function defined by W e^W = x.
0044  *
0045  * -1/E < x < \infty
0046  *
0047  * exceptions: GSL_EMAXITER;
0048  */
0049 int     gsl_sf_lambert_W0_e(double x, gsl_sf_result * result);
0050 double  gsl_sf_lambert_W0(double x);
0051
0052
0053 /* Lambert's Function W_{-1}(x)
0054  *
0055  * W_{-1}(x) is the second real branch of the
0056  * implicit function defined by W e^W = x.
0057  * It agrees with W_0(x) when x >= 0.
0058  *
0059  * -1/E < x < \infty
0060  *
0061  * exceptions: GSL_MAXITER;
0062  */
0063 int     gsl_sf_lambert_Wm1_e(double x, gsl_sf_result * result);
0064 double  gsl_sf_lambert_Wm1(double x);
0065
0066
0067 __END_DECLS
0068
0069 #endif /* __GSL_SF_LAMBERT_H__ */