On Mar 13, 4:34 pm, Julien PUYDT <julien.pu...@laposte.net> wrote: > Hi, > > among the few failing tests with my ARM built, two are because of > accuracy reasons : > > File "/home/jpuydt/sage-4.6.2/devel/sage/sage/functions/other.py", line 497: > sage: gamma1(float(6)) > Expected: > 120.0 > Got: > 119.99999999999997
Why are we even testing the behaviour on floats? Isn't sage's default floating point type RDF? sage: a=float(119.99999999999997) sage: a 119.99999999999997 sage: RDF(a) 120.0 sage: float(RDF(a)) 119.99999999999997 CPython explicitly defers to the C it is compiled with to define the behaviour or "float". See sys.float_info for more information. It's a bit ridiculous to test verbatim behaviour for something that is defined to be varying (although you may want to doctest exactly that to be aware of possible sources of different behaviour on different platforms). Anyway, "RDF" has a lot more tolerant printing behaviour than "float" -- I guess Python's printing produces enough decimal digits to faithfully reconstruct the binary representation? Doctesting RDF(gamma1(float(6.0))) would probably test float arithmetic but print the result in a way that it is easier to pass doctests, without allowing for very big inaccuracies. -- 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
