On 1/29/07, Keith Goodman <kwgoodman@gmail.com> wrote:
On 1/27/07, Charles R Harris <charlesr.harris@gmail.com> wrote:
> Oddly, the relative error is always the same:
>
> 98 z different 2.0494565872e-16
> 99 z different 2.0494565872e-16
>
> Which is nearly the same as the double precision 2.2204460492503131e-16, the
> difference being due to the fact that the precision is defined relative to
> 1, and the error in the computation are in a number relatively larger (more
> bits set, but not yet 2).
Fernando (Ubuntu) and I (Debian) get a different result
(8.47032947254e-22) than you (Fedora) do (2.0494565872e-16).
That's odd, the LSB bit of the double precision mantissa is only about
2.2e-16, so you can't *get* differences as small as 8.4e-22 without about 70 bit mantissa's. Hmmm, and extended double precision only has 63 bit mantissa's. Are you sure you are computing the error correctly?
Chuck