Craig Citro wrote:
> So there are two things people could want from an interval i:
>
> 1) { floor(x) for x in i }
> 2) min { floor(x) for x in i }
>
> I think that David's unhappy with floor doing (2). The other proposal
> is to have x.floor() return the unique element in (1) when it's a
> singleton, and raise an exception otherwise. David -- would you be
> happy with that?
>
I really think that floor, ceil, and round should return intervals when
they are fed intervals. I thought that was the whole point of interval
arithmetic. Shouldn't sin(floor(interval)) be an interval? It won't
be if floor automatically converts things to integers. Why should
floor, ceil, and round get special treatment to yank things out of
interval arithmetic? Why not other functions too? It seems that having
some functions that yank you out of interval arithmetic sort of spoil
everything.
I really like the idea that we should have separate ifloor, iceil, and
iround functions specifically on intervals that return integers, as
described.
That said, I don't use interval arithmetic very much at all (so my
points above are purely from a consistency point of view). However, I
do plan on using it in teaching numerical analysis next semester.
Thanks,
Jason
--
Jason Grout
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