Re: Numerical accuracy/precision - this is a bug or a feature?

*To*: mathgroup at smc.vnet.net*Subject*: [mg120321] Re: Numerical accuracy/precision - this is a bug or a feature?*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Tue, 19 Jul 2011 06:54:38 -0400 (EDT)

Mathematica will not allow you to prove that 1 == 0. It says False! Perhaps you, a human, would wish to deduce something opposite, from results that are contrary to other conventions or expectation. But still, Mathematica knows what's what here. And even that 2 + 2 == 7 is False. On 7/18/11 6:13 AM, slawek wrote: > > ...Mathematica uses a different convention. By default, assumes that numbers > such as 1.4 or 2.0 are inaccurate. It is even worse, because though a == b > is True, then N [a] and N [b] are not the same. Hence we can prove that 1 == > 0, or if you prefer that 2 +2 == 7 . > > It is a feature, but in my opinion it may leads to serious bugs. > > slawek > > > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305