| @cindex logarithm and related functions |
| |
| Information on the properties of the Logarithm function can be found in |
| Abramowitz & Stegun, Chapter 4. The functions described in this section |
| are declared in the header file @file{gsl_sf_log.h}. |
| |
| @deftypefun double gsl_sf_log (double @var{x}) |
| @deftypefunx int gsl_sf_log_e (double @var{x}, gsl_sf_result * @var{result}) |
| These routines compute the logarithm of @var{x}, @math{\log(x)}, for |
| @math{x > 0}. |
| @comment Exceptional Return Values: GSL_EDOM |
| @end deftypefun |
| |
| |
| @deftypefun double gsl_sf_log_abs (double @var{x}) |
| @deftypefunx int gsl_sf_log_abs_e (double @var{x}, gsl_sf_result * @var{result}) |
| These routines compute the logarithm of the magnitude of @var{x}, |
| @math{\log(|x|)}, for @math{x \ne 0}. |
| @comment Exceptional Return Values: GSL_EDOM |
| @end deftypefun |
| |
| |
| @deftypefun int gsl_sf_complex_log_e (double @var{zr}, double @var{zi}, gsl_sf_result * @var{lnr}, gsl_sf_result * @var{theta}) |
| This routine computes the complex logarithm of @math{z = z_r + i |
| z_i}. The results are returned as @var{lnr}, @var{theta} such that |
| @math{\exp(lnr + i \theta) = z_r + i z_i}, where @math{\theta} lies in |
| the range @math{[-\pi,\pi]}. |
| @comment Exceptional Return Values: GSL_EDOM |
| @end deftypefun |
| |
| |
| @deftypefun double gsl_sf_log_1plusx (double @var{x}) |
| @deftypefunx int gsl_sf_log_1plusx_e (double @var{x}, gsl_sf_result * @var{result}) |
| These routines compute @math{\log(1 + x)} for @math{x > -1} using an |
| algorithm that is accurate for small @math{x}. |
| @comment Domain: x > -1.0 |
| @comment Exceptional Return Values: GSL_EDOM |
| @end deftypefun |
| |
| |
| @deftypefun double gsl_sf_log_1plusx_mx (double @var{x}) |
| @deftypefunx int gsl_sf_log_1plusx_mx_e (double @var{x}, gsl_sf_result * @var{result}) |
| These routines compute @math{\log(1 + x) - x} for @math{x > -1} using an |
| algorithm that is accurate for small @math{x}. |
| @comment Domain: x > -1.0 |
| @comment Exceptional Return Values: GSL_EDOM |
| @end deftypefun |
