On Fri, Aug 12, 2016 at 9:42 AM, Jeroen Demeyer <jdeme...@cage.ugent.be> wrote: > On 2016-08-11 12:24, Erik Bray wrote: >> >> In this case the difference is just one ulp. > > > To be more precise: the difference is actually about 0.59 ulp on Cygwin: > > sage: R = RealField(256) > sage: log3_exact = R(3).log() > sage: log3_cygwin = RDF(1.0986122886681096) > sage: (R(log3_cygwin) - log3_exact)/log3_cygwin.ulp() > -0.5914650915268009
Oh nice, I did't know you could do that. In the above I meant the difference between the result I had on Linux and on Cygwin which of course have the same floating point precision, not the difference from the (closer to) exact value. Using the same calculation as above the difference of the Linux result from exact is ~0.41 ulp. All the more reason to just add a small tolerance on this particular test. Thanks again! -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
