Function qagpe
void qagpe(Real, Func)
(
Func f,
Real a,
Real b,
int npts2,
const Real* points_,
Real epsabs,
Real epsrel,
int limit,
out Real result,
out Real abserr,
out int neval,
out int ier,
Real* alist_,
Real* blist_,
Real* rlist_,
Real* elist_,
Real* pts_,
int* iord_,
int* level_,
int* ndin_,
out int last
);