Eigs again - Success!!

[John W. Eaton]

On  4-Nov-2006, David Bateman wrote:

| The fix is a simple 5 line change to xNEUPD.f in ARPACK, to force the M
| output of xTRSEN to not exceed the original NCONV value. I've reported
| the error to the maintainers of ARPACK and will see if there is any
| follow-up. In any case with the above change I can no longer generate
| the segfault even after millions of iterations of the segtest code.. I
| attach the ARPACK patch, last version of eigs and the test code for
| those that are interested.

Any response to that yet?  I suppose the worst case would be that we
would have to distribute a patch for ARPACK with Octave.  Would it be
possible to test for the bug in the configure script?

| Basically, before finally submitting this function I'd like to split
| eigs up into a number of classes, and use these template classes to
| allow both sparse and full cases to be treated. So I hope to have
| something relatively soon. So after 18 months of on again off again work
| on eigs, I think I finally have something I can be confident in :-)

It would be better if the core of Feigs could be smaller, and if the
functionality it provides is also more easily available from
liboctave, but that's not essential.

Thanks,

jwe