In Ruby/GSL, series acceleration functions are provided as singleton methods
for the GSL::Sum::Levin_u, Levin_utrunc classes, and methods of
an object of the GSL::Vector class.
GSL::Sum::Levin_u.alloc(size)GSL::Sum::Levin_utrunc.alloc(size)GSL::Sum::Levin_u.accel(v)[sum, abserr, sum_plain, terms_used],
where sum is the extrapolated sum, abserr is an estimate of the
absolute error, and sum_plain is the actual term-by-term sum.GSL::Sum::Levin_utrunc.accel(v)[sum, abserr_trunc, sum_plain, terms_used].GSL::Sum::Levin_u#accel(v)GSL::Sum::Levin_u#sum_plainGSL::Sum::Levin_u#terms_usedGSL::Sum::Levin_utrunc#accel(v)GSL::Sum::Levin_utrunc#sum_plainGSL::Sum::Levin_utrunc#terms_usedGSL::Vector#accelGSL::Vector#accel_sumGSL::Vector#sum_accelGSL::Vector#sum