On Sep 29, 2011, at 5:11 PM, Mark Engelberg wrote: > How is it possible to have an inexact integer?
That threw me, too, the first time I encountered it. Where do inexact numbers come from? Two common sources: physical measurement, and computations whose exact results can't be represented in any of the standard numeric formats. So for example the location of the mouse is a physical measurement, and therefore inherently inexact. However, it's measured in pixels, so it's an integer (or rather a pair of integers). Now, how about an inexact computation whose result, to within rounding error, is an integer? (define x #i1.000000000000001) x ; not 1 (sqrt x) ; #i1.0000000000000004 (sqrt (sqrt x)) ; #i1.0000000000000002 (sqrt (sqrt (sqrt x))) ; #i1.0 But mathematically, the answer shouldn't be 1 because it's the square root of something that wasn't 1, so the "inexact" marker is correct. Stephen Bloch sbl...@adelphi.edu _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
