On Thu, Jun 14, 2018 at 01:44:34PM -0500, Tim Peters wrote: > I should note that numeric code "that works" is often much subtler than it > appears at first glance. So, for educational purposes, I'll point out some > of what _wasn't_ said about this crucial function: [...]
Thanks Tim! Reading your digressions on the minutia of floating point maths is certainly an education. It makes algebra and real-valued mathematics seem easy in comparison. I still haven't got over Mark Dickinson's demonstration a few years back that under Decimal floating point, but not binary, it is possible for the ordinary arithmetic average (x+y)/2 to be outside of the range [x, y]: py> from decimal import getcontext, Decimal py> getcontext().prec = 3 py> x = Decimal('0.516') py> y = Decimal('0.518') py> (x + y) / 2 Decimal('0.515') -- Steve _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/