Thank you Raul and Mike. I wrote:
> Eigenvalues again. For structural dynamics it is the generalised > Eigenvalue problem that is needed, the solution to > > (A - w B) r = 0 > > where A and B are real square matrices, w the eigenvalue and r is the > eigenvector. Raul asked: > For your case are A and B known, and w and r unknown? Or something different? Yes, A and B are known, and w and r are unknown. Mike suggested: > There's a dgegv.f in ~\addons\math\lapack . Its preamble comments say it's deprecated in favour of dggev... so are you looking for an implementation of dggev.ijs? Yes, I read that too. Though dgegv does what I want, maybe dggev is more accurate. I have subsequently found that at the moment I don't need either of them, because for the typical problems I am attempting B is always a unit matrix, so all I need is dgeev, which I've got. Thanks for your help. Sorry for the false alarm. Graham ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
