On 12/28/10 10:42 AM, Oliver Kullmann wrote:
> On the other hand, the difference of
>
> 4.830986538632788-4.83098653863282 ~ -3.197442310920451e-14
>
> is gigantic (so well, at least to me ;-)) ?
Yes, that is a bit larger than we want. One solution would be to ask
your lisp vendor to have it signal an error on log(<really big
integer>). Then the loss of accuracy only happens when there is a big
integer.
But I can also change the code to do an explicit check for the range
when using gcl and ecl. That might be ok.
>
> Aha, thus it got slower. So well, it seems we need to lower our
> expectations for some time ...
Not according to your results. 5.22 was 10 sec faster when running
testf1 than 5.21.
But if you look at $float, there is a huge amount of processing before
we get to part that computes the actual log. I suspect there isn't
much extra caused by the extra computations.
Ray