> El 14 oct 2016, a las 0:32, Peetz, Darin T <pee...@illinois.edu> escribió: > > I've come across an irregularity when extracting the eigenvectors when using > the CISS method to solve the eigenvalue problem. I'm solving a generalized > hermitian problem, and it looks like the resulting eigenvectors are > M-orthogonalized with each other (the M-inner products of different > eigenvectors are approximately 0, as expected), but are normalized using the > L2-inner product, not the M-inner product. Basically, the matrix V'*M*V (V > being a matrix composed of the extracted eigenvectors) is diagonal, but the > diagonals are much larger than 1, and the matrix V'*V has non-zero diagonals, > but the diagonal elements are exactly equal to 1. > > This only happens if I use the CISS method. If I use the Arnoldi method for > example, the eigenvectors are normalized as expected. Is there any > particular reason for this, or is this an error in the implementation? > > Thanks, > Darin
Thanks for reporting this. The fix is to add this line: eps->purify = PETSC_FALSE; anywhere in function EPSSetUp_CISS() (in file src/eps/impls/ciss/ciss.c). I will include the fix for future releases. Jose