7.6 Clausen Functions

The Clausen function is defined by the following integral, It is related to the dilogarithm by Cl_2(\theta) = \Im Li_2(\exp(i\theta)). The Clausen functions are declared in the header file ‘gsl_sf_clausen.h’.

Function: double gsl_sf_clausen (double x)

Function: int gsl_sf_clausen_e (double x, gsl_sf_result * result)

These routines compute the Clausen integral Cl_2(x).