Hi,
2007/6/9, Dann Corbit <DCorbit@connx.com>:
> It makes sense with factorial function to do an error check on the
> domain. Calculate beforehand, and figure out what the largest sensible
> domain value is.
well, in fact what we need is to calculate log10(n!) first to see if
the result will get exceeded.
>
> For instance, in Maple, I get this:
> > y:=92838278!;
> Error, object too large
> >
>
> The error message returns instantly.
>
> For reasonably large values, it might make sense to pre-compute
> factorials and store them in an array.
>It should also be possible to
> store 1/2 of Pascal's triangle in memory and demand load that memory
> segment the first time someone asks for factorials or combinations or
> permutations.
there may be too much memories to waste in that case... :-(
Regards
CUI Shijun
