On 1/29/07, Keith Goodman <[EMAIL PROTECTED]> wrote:
On 1/27/07, Charles R Harris <[EMAIL PROTECTED]> 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
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