Le Sun, 5 Feb 2012 20:03:48 -0800, Jonathan Bober <jwbo...@gmail.com> a écrit : > The source code does say: > > In extensive but non-exhaustive > random tests, this function proved accurate to within <= 10 ulps > across the > entire float domain. Note that accuracy may depend on the quality > of the system math functions, the pow function in particular. > > So if the accuracy of pow() in eglicb relies on long doubles, then > there may be a problem, but maybe it will work well there.
Within 10 ulp? Look at the comment at the start of [1], where they explain how they compute things, then explain the accuracy: * Accuracy: Gamma(x) is accurate to within * x > 0: error provably < 0.9ulp. * Maximum observed in 1,000,000 trials was .87ulp. * x < 0: * Maximum observed error < 4ulp in 1,000,000 trials. This looks pretty good! Snark on #sagemath [1] http://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/src/lib/libm/noieee_src/n_gamma.c -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
