[Ecls-list] How might this elliptic_e issue on SPARC hardware with ECL be debugged?

Dr. David Kirkby david.kirkby at onetel.net
Mon Aug 10 07:42:44 UTC 2009

You probably see my previous posts on the fact that elliptic_e is giving 
incorrect results on SPARC hardware using ECL. If not,


has the details.

Can anyone who knows the internals of Maxima tell me what standard 
libraries supplied with Solaris the functions 'elliptic_e' might be 
expected to call?

Looking in a maths book, I see some formula with sin() in them, 
suggesting an incorrect result from sin(x) might mess the computation of 
an elliptic integral. A few quick checks with sin() on Sage showed no 
obvious differences from those computed in Mathematica.

Is there anything else that could be suspected, and so narrow down the 
list of possible causes somewhat?

Sage can certainly be eliminated, as the problem is seen when I call 
Maxima directly. Things that can't be totally eliminated, but some are 
very unlikly, include:

* Hardware fault on the particular machine.
* Design flaw in Sun UltraSPARC CPU (remember the Pentium floating point 
bug, which must have cost Intel a fortune?)
* Solaris library bug
* Maxima
* gcc
* I screwed up compiling Maxima or ECL.

I hope to eliminate the possibility of a hardware fault by copying the 
binaries to another Sun.

I believe ECL will build with Sun's compiler, so I can try to eliminate 
gcc as the culprit.

Can anyone with a better maths background suggest other ways the 
possible range of issues could be narrowed down?

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