Error from Big Combinations



On Tue, Dec 9, 2008 at 6:18 AM, Thomas La Bone <labone at gforcecable.com>wrote:

> ... I get an error from 8000 choose 800:
>   float(combination(8000,800));...
>


> Mathematica gives me an answer of something like 2.819E+1040. Is the
> error the result of Maxima not being able to represent such a large
> floating point number?
>

Maxima can certainly represent such a large number, using its "bigfloat"
system.  To convert the exact integer result given by combination(8000,800)
to a bigfloat, use bfloat.

On the other hand, standard machine floating-point (IEEE floating point)
cannot represent numbers greater than about 10^308.  This is not a Maxima
limitation, but a machine limitation.  float(...) converts to machine
floats.

            -s