On Sat, Oct 29, 2011 at 16:44, Robert Dodier <robert.dodier at gmail.com>wrote:
> ...Well, I'd like to see stuff like this: compute the mean / variance / etc
> of [a, b, c] where a, b, and c are symbols, intervals, objects which
> represent some special-purpose implementation (e.g. multiple precision
> numbers), expressions like 2 i + 3 j - 4 k, dimensional quantities
> (feet, meters, etc), or ordinary numbers, or combinations thereof.
>
Well, yes, right now, neither Maxima nor R can deal with arbitrary-type
arithmetic objects for most operations. R, though it has a wealth of
object systems (some standard and others added on), has no standard
functions which can operate with opaque arithmetic types.
Maxima almost succeeds in supporting bigfloats everywhere it supports
floats, but not quite, so adding anything that doesn't behave like a number
is probably a fair amount of work (e.g. for intervals, trichotomy doesn't
hold).
Of course, Maxima has the advantage that it does support arbitrary symbolic
expressions, so it doesn't assume things like trichotomy in general.
Still, I don't see that anyone has succeeded in building a reasonably
complete and efficient interval arithmetic system on top of it.
A good goal, though.
-s