/* specfunc/gsl_sf_log.h
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000 Gerard Jungman
*
* 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, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* Author: G. Jungman */
#ifndef __GSL_SF_LOG_H__
#define __GSL_SF_LOG_H__
#include <gsl/gsl_sf_result.h>
#undef __BEGIN_DECLS
#undef __END_DECLS
#ifdef __cplusplus
# define __BEGIN_DECLS extern "C" {
# define __END_DECLS }
#else
# define __BEGIN_DECLS /* empty */
# define __END_DECLS /* empty */
#endif
__BEGIN_DECLS
/* Provide a logarithm function with GSL semantics.
*
* exceptions: GSL_EDOM
*/
int gsl_sf_log_e(const double x, gsl_sf_result * result);
double gsl_sf_log(const double x);
/* Log(|x|)
*
* exceptions: GSL_EDOM
*/
int gsl_sf_log_abs_e(const double x, gsl_sf_result * result);
double gsl_sf_log_abs(const double x);
/* Complex Logarithm
* exp(lnr + I theta) = zr + I zi
* Returns argument in [-pi,pi].
*
* exceptions: GSL_EDOM
*/
int gsl_sf_complex_log_e(const double zr, const double zi, gsl_sf_result * lnr, gsl_sf_result * theta);
/* Log(1 + x)
*
* exceptions: GSL_EDOM
*/
int gsl_sf_log_1plusx_e(const double x, gsl_sf_result * result);
double gsl_sf_log_1plusx(const double x);
/* Log(1 + x) - x
*
* exceptions: GSL_EDOM
*/
int gsl_sf_log_1plusx_mx_e(const double x, gsl_sf_result * result);
double gsl_sf_log_1plusx_mx(const double x);
#if HAVE_EXTERN_INLINE
extern inline
int
gsl_sf_log_e(const double x, gsl_sf_result * result)
{
/* CHECK_POINTER(result) */
if(x <= 0.0) {
result->val = GSL_NAN;
result->err = GSL_NAN;
GSL_ERROR ("domain error", GSL_EDOM);
}
else {
result->val = log(x);
result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val);
return GSL_SUCCESS;
}
}
extern inline
int
gsl_sf_log_abs_e(const double x, gsl_sf_result * result)
{
/* CHECK_POINTER(result) */
if(x == 0.0) {
result->val = GSL_NAN;
result->err = GSL_NAN;
GSL_ERROR ("domain error", GSL_EDOM);
}
else {
result->val = log(fabs(x));
result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val);
return GSL_SUCCESS;
}
}
#endif /* HAVE_EXTERN_INLINE */
__END_DECLS
#endif /* __GSL_SF_LOG_H__ */