On Thu, Apr 8, 2010 at 7:29 PM, Doug Burke <doug_j_bu...@yahoo.com> wrote:
> > --- On Thu, 4/8/10, Gregory Crosswhite <gcr...@phys.washington.edu> wrote: > > > From: Gregory Crosswhite <gcr...@phys.washington.edu> > > > > > On a tangental note, I've considered coding up a package > > with an "AlmostEq" typeclass that allows one to test for > > approximate equality. The problem is that different > > situations call for different tolerances so there is no > > standard "approximate equal" operator that would work for > > everyone, but there might be a tolerance that is "good > > enough" for most situations where it would be needed (such > > as using QuickCheck to test that two different > > floating-point functions that are supposed to return the > > same answer actually do so) to make it worthwhile to have a > > standard package for this around for the sake of > > convenience. > > > > Anyone have any thoughts on this? > I've always wondered if Haskell would make it easy to track number of significant digits. The other thought is that you could probably use Oleg's implicit configurations to handle the tolerance in a rather nice way: http://www.cs.rutgers.edu/~ccshan/prepose/prepose.pdf The example in the paper is managing the modulus implicitly and I would imagine the amount of precision could be managed similarly. Jason
_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
