This is now #12968 <http://trac.sagemath.org/sage_trac/ticket/12968>. (I couldn't find a ticket for it, but the problem was documented in the source code (see other answers to that posting). Does someone know that there is a ticket for it already?)
Am Sonntag, 13. Mai 2012 18:50:11 UTC+2 schrieb Lorenzo: > > Hi everyone, first time sage user here. > > I am puzzled by the behavior of round(): > > sage: t=sqrt(4320373582484102551677386613153502) > sage: floor(t) > 65729548777426599 > sage: round(t) #everything as expected, floor ≤ round ≤ ceil > 65729548777426600 > sage: ceil(t) > 65729548777426600 > sage: u = sqrt(43203735824841025516773866131535024) #add one digit > sage: floor(u) > 207855083711803944 > sage: round(u) # ?? smaller than floor(u)! No warning message... > 207855083711803936 > sage: r = round(u) > sage: ceil(u) > 207855083711803945 > sage: type(r) # seems to have still the same precision...? (i.e., it > wasn’t converted to some "float type" – I admit of course that I don't know > how the sage type system works) > <type 'sage.rings.integer.Integer'> > sage: version() > 'Sage Version 4.8, Release Date: 2012-01-20' > > uname -a > Darwin iMac.local 10.8.0 Darwin Kernel Version 10.8.0: Tue Jun 7 16:33:36 > PDT 2011; root:xnu-1504.15.3~1/RELEASE_I386 i386 > > Can someone explain this behavior? If this isn’t a bug, it is a very > unintuitive "feature" for sage-neophytes, to say the least. > > Thank you very much! > -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
