Oscar Benjamin added the comment: On 22 August 2013 03:43, Steven D'Aprano <rep...@bugs.python.org> wrote: > > If Oscar is willing, I'd like to discuss some of his ideas off-list, but that > may take some time.
I am willing and it will take time. I've started reading the paper that Raymond Hettinger references for the algorithm used in his accurate float sum recipe. I'm not sure why yet but the algorithm is apparently provably exact only for binary radix floats so isn't appropriate for decimals. It does seem to give *very* accurate results for decimals though so I suspect the issue is just about cases that are on the cusp of the rounding mode. In any case the paper cites a previous work that gives an algorithm that apparently works for floating point types with arbitrary radix and exact rounding; it would be good for that to live somewhere in Python but I haven't had a chance to look at the paper yet. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue18606> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
