Raymond Toy wrote:
Thank you for your interest, i see there is no way to recompile a particular
fasl as i feared.
>
> Anyway, I ran your test after compiling eigens-by-jacobi.lisp for sse2.
> I get pretty much the same plot there as I do on a Sun sparc machine.
>
> Can you tell me what the smallest and largest eigenvalues you get? For
> sse2, I get:
> - 2.045740417937529 and 2.876115587743105
>
> These are exactly the same values on sparc.
I get exactly these same values on my laptop which doesn't have .sse2
binaries, but .xf86 ones.
I have also computed with bfloats (fppprec:80) which takes 5mn
instead of 3s, but gives the same result up to 15 significative figures.
So i think these are correct. But yesterday, on my colleague macbook,
the extreme values where like -4 and +6, while values in between looked
correct.
There is another potential problem, the plot produced has a "glitch" around
80 (horizontal axis). I certainly get that here, even computing with
bfloats. My colleague has just sent me the graphs computed with maxima and
mathematica, and the last one doesn't have any glitch. I have put a copy of
the graphs here:
http://www.lpthe.jussieu.fr/~talon/Spin_50.pdfhttp://www.lpthe.jussieu.fr/~talon/spin50_Mathematica.pdf
so maybe there is another problem somewhere. Anyways, it is wonderful how
the eigenvalues are regularly spaced for this matrix,this is very unusual.
>
> What version of cmucl are you using? I did the test using 2009-01.
>
> Ray
It was cmucl-2009-02-x86-darwin.tar.bz2
--
Michel Talon