7.17.1 Exponential Integral

Function: double gsl_sf_expint_E1 (double x)

Function: int gsl_sf_expint_E1_e (double x, gsl_sf_result * result)

These routines compute the exponential integral E_1(x),

Function: double gsl_sf_expint_E2 (double x)

Function: int gsl_sf_expint_E2_e (double x, gsl_sf_result * result)

These routines compute the second-order exponential integral E_2(x),

Function: double gsl_sf_expint_En (int n, double x)

Function: int gsl_sf_expint_En_e (int n, double x, gsl_sf_result * result)

These routines compute the exponential integral E_n(x) of order n,