Of course something like check-within is what is needed. The point is: there ought to be something like check-within that can be used in a function to test "equality within a delta".
I suppose it's fine for each student to define one herself; I'm just saying I think it's so important it ought to be built-in. Best, John On Tue, Oct 04, 2011 at 02:23:16PM -0400, Shriram Krishnamurthi wrote: > check-within > > http://docs.racket-lang.org/test-engine/index.html#(def._((lib._test-engine/racket-tests..rkt)._check-within)) Yes. That's exactly what students should be using ubstead of anything that even looks like an equality-test. The only time you'd want an actual equality test on inexact numbers is whan you're using it algorithmically instead of numerically, such as attaching a memo-pad to a function on inexactt numbers. _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
