Elemental also has distributed-memory eigensolvers that should be at least as good as ScaLAPACK's. There is support for Elemental in PETSc, but not yet in SLEPc.
"Povolotskyi, Mykhailo via petsc-users" <petsc-users@mcs.anl.gov> writes: > Thank you for suggestion. > > Is it interfaced to SLEPC? > > > On 08/29/2019 04:14 PM, Jose E. Roman wrote: >> I am not an expert in contour integral eigensolvers. I think difficulties >> come with corners, so ellipses are the best choice. I don't think ring >> regions are relevant here. >> >> Have you considered using ScaLAPACK. Some time ago we were able to address >> problems of size up to 400k https://doi.org/10.1017/jfm.2016.208 >> >> Jose >> >> >>> El 29 ago 2019, a las 21:55, Povolotskyi, Mykhailo <mpovo...@purdue.edu> >>> escribió: >>> >>> Thank you, Jose, >>> >>> what about rings? Are they better than rectangles? >>> >>> Michael. >>> >>> >>> On 08/29/2019 03:44 PM, Jose E. Roman wrote: >>>> The CISS solver is supposed to estimate the number of eigenvalues >>>> contained in the contour. My impression is that the estimation is less >>>> accurate in case of rectangular contours, compared to elliptic ones. But >>>> of course, with ellipses it is not possible to fully cover the complex >>>> plane unless there is some overlap. >>>> >>>> Jose >>>> >>>> >>>>> El 29 ago 2019, a las 20:56, Povolotskyi, Mykhailo via petsc-users >>>>> <petsc-users@mcs.anl.gov> escribió: >>>>> >>>>> Hello everyone, >>>>> >>>>> this is a question about SLEPc. >>>>> >>>>> The problem that I need to solve is as follows. >>>>> >>>>> I have a matrix and I need a full spectrum of it (both eigenvalues and >>>>> eigenvectors). >>>>> >>>>> The regular way is to use Lapack, but it is slow. I decided to try the >>>>> following: >>>>> >>>>> a) compute the bounds of the spectrum using Krylov Schur approach. >>>>> >>>>> b) divide the complex eigenvalue plane into rectangular areas, then >>>>> apply CISS to each area in parallel. >>>>> >>>>> However, I found that the solver is missing some eigenvalues, even if my >>>>> rectangles cover the whole spectral area. >>>>> >>>>> My question: can this approach work in principle? If yes, how one can >>>>> set-up CISS solver to not loose the eigenvalues? >>>>> >>>>> Thank you, >>>>> >>>>> Michael. >>>>>
