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 `gsl_sf_log.h'.
- Function: double gsl_sf_log (double x)
-
- Function: int gsl_sf_log_e (double x, gsl_sf_result * result)
-
These routines compute the logarithm of x, \log(x), for
x > 0.
- Function: double gsl_sf_log_abs (double x)
-
- Function: int gsl_sf_log_abs_e (double x, gsl_sf_result * result)
-
These routines compute the logarithm of the magnitude of x,
\log(|x|), for x \ne 0.
- Function: int gsl_sf_complex_log_e (double zr, double zi, gsl_sf_result * lnr, gsl_sf_result * theta)
-
This routine computes the complex logarithm of z = z_r + i
z_i. The results are returned as lnr, theta such that
\exp(lnr + i \theta) = z_r + i z_i, where \theta lies in
the range [-\pi,\pi].
- Function: double gsl_sf_log_1plusx (double x)
-
- Function: int gsl_sf_log_1plusx_e (double x, gsl_sf_result * result)
-
These routines compute \log(1 + x) for x > -1 using an
algorithm that is accurate for small x.
- Function: double gsl_sf_log_1plusx_mx (double x)
-
- Function: int gsl_sf_log_1plusx_mx_e (double x, gsl_sf_result * result)
-
These routines compute \log(1 + x) - x for x > -1 using an
algorithm that is accurate for small x.