New submission from Gregory P. Smith: This is a very odd inconsistency in math.log behavior. That said, it is probably only a single bit imprecision at the end of the float result. Still, 10 == 10L so I'd expect math.log of both to give the same result.
oss/cpython/2.7:LOAS$ ./python Python 2.7.5+ (2.7:395ac61ebe1a, Aug 14 2013, 07:11:35) [GCC 4.6.3] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import math >>> math.log(10) - math.log(10L) 4.440892098500626e-16 >>> math.log(10) 2.302585092994046 >>> math.log(10L) 2.3025850929940455 >>> In Python 3.3 things seem fine and match the int behavior from 2.7 above despite the internal number implementation being a PyLong in 3.x: >>> math.log(10) 2.302585092994046 ---------- messages: 195175 nosy: gregory.p.smith priority: normal severity: normal status: open title: math.log of a long returns a different value of math.log of an int versions: Python 2.7 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue18739> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
