On Wed, Feb 26, 2014 at 2:41 PM, Qin Lu <[email protected]> wrote:
> Hello, > > I need to find the spectrum of the a large linear system (over 100,000 > unknowns). Option -ksp_compute_eigenvalues_explicitly ran out of memory > since the matrix is too big, then -ksp_compute_eigenvalues only gave a > small number of eigenvalues (around 30). My questions are: > > 1. Is the number of computed eigenvalues determined by the number of GMRES > iterations to converge? > 2. Can PETSc give the extreme eigenvalues now that the number of computed > eigenvalues is limited? > It will help to understand why you want these. Matt > Thanks a lot for your info, > Qin > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
