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Diffstat (limited to 'gsl-1.9/doc/specfunc-log.texi')
| -rw-r--r-- | gsl-1.9/doc/specfunc-log.texi | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/gsl-1.9/doc/specfunc-log.texi b/gsl-1.9/doc/specfunc-log.texi new file mode 100644 index 0000000..75279e8 --- /dev/null +++ b/gsl-1.9/doc/specfunc-log.texi @@ -0,0 +1,47 @@ +@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 |