gsl_sf_log
Signature: (double x(); double [o]y(); double [o]e())
Provide a logarithm function with GSL semantics.
gsl_sf_log does not process bad values. It will set the bad-value flag of all output ndarrays if the
flag is set for any of the input ndarrays.
gsl_sf_complex_log
Signature: (double zr(); double zi(); double [o]x(); double [o]y(); double [o]xe(); double [o]ye())
Complex Logarithm exp(lnr + I theta) = zr + I zi Returns argument in [-pi,pi].
gsl_sf_complex_log does not process bad values. It will set the bad-value flag of all output ndarrays if
the flag is set for any of the input ndarrays.