Erik Bray wrote: > 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!
Yeah, the doctest framework should automatically base the tolerance on such comparisons... ;-) :P -leif -- 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.
