Re: numeric precision when raising one numeric to another.

At CONNX, we just do 100 digits using qfloat (about 104 actually).
Internally, all math is done using this type. Then we convert to the
smaller types [or character types] as requested.

I don't think that there is any business need for more than that.

A package like Maple might need to worry about it, or a theoretical
mathematician looking for patterns in digits or something like that.

But you can't please everybody.

> -----Original Message-----
> From: pgsql-general-owner(at)postgresql(dot)org [mailto:pgsql-general-
> owner(at)postgresql(dot)org] On Behalf Of Martijn van Oosterhout
> Sent: Thursday, May 19, 2005 2:48 PM
> To: Dann Corbit
> Cc: Alvaro Herrera; John Burger; pgsql-general(at)postgresql(dot)org
> Subject: Re: [GENERAL] numeric precision when raising one numeric to
> another.
>
> On Thu, May 19, 2005 at 02:25:58PM -0700, Dann Corbit wrote:
> > Hmmm....
> > I underestimated.
> >
> > pow(99999.99999,99999.99999) =
>
> Yeah, a number with x digits raised to the power with something y
digits
> long could have a length approximating:
>
> x * (10^y) digits
>
> So two numbers both 4 digits long can have a result of upto 40,000
> digits. You're only going to be able to them represent exactly for
> cases where y is small and integer.
>
> What's a meaningful limit? Do we simply say, you get upto 100 digits
> and that's it? Or an extra parameter so you can specify directly?
> --
> Martijn van Oosterhout <kleptog(at)svana(dot)org>
http://svana.org/kleptog/
> > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent
is a
> > tool for doing 5% of the work and then sitting around waiting for
> someone
> > else to do the other 95% so you can sue them.