I'm bumping into the old "Eigenvalues did not converge" error using numpy.linalg.eigh() on several different linux builds of numpy (1.4.1). The matrix is 166x166. I can compute the eigenvalues on a Macintosh build of numpy, and I can confirm that there aren't degenerate eigenvalues, and that the matrix appears to be negative definite.

I've seen this before (though not for several years), and what I normally do is to build lapack with -O0. This trick did not work in the current instance. Does anyone have any tricks to getting eigh to work?

Other weird things that I've noticed about this case: I can compute the eigenvalues using eigvals and eigvalsh, and can compute the eigenvals/vecs using eig(). The matrix is real symmetric, and I've tested that it's symmetric enough by forcibly symmetrizing it.

Thanks in advance for any help you can offer.

Rick Muller