Looks good but it only gives 4 eigenvalues. How do I get the 50 smallest eigenvalues?
---John On Tue, Aug 2, 2011 at 3:40 AM, Jose E. Roman <jroman at dsic.upv.es> wrote: > > El 02/08/2011, a las 09:24, John Chludzinski escribi?: > > > Jose, > > > > I used: > > > > MatCreateSeqAIJ(PETSC_COMM_SELF, n, n, 0, cnt, &A); > > MatSetValue(A, i, j, *(a+i*SIZE+j), INSERT_VALUES); > > > > to create the input matrices. Their sizes collapsed dramatically: from > 192208072 to 239944. But again, using: ./ex7.exe -f1 k.dat -f2 m.dat > -eps_gen_hermitian -eps_smallest_real > x.out 2>&1, I get: > > > > Generalized eigenproblem stored in file. > > > > Reading REAL matrices from binary files... > > Number of iterations of the method: 500 > > Number of linear iterations of the method: 4009 > > Solution method: krylovschur > > > > Number of requested eigenvalues: 1 > > Stopping condition: tol=1e-07, maxit=500 > > Number of converged approximate eigenpairs: 0 > > > > I'm really only interested in the least 50 eigenvalues. > > > > Smallest 10 eigenvalues > > -0.000019 > > -0.000004 > > -0.000000 > > 0.000005 > > 0.000012 > > 0.000016 > > 2.795284 > > 2.795307 > > 21.235339 > > 21.235340 > > 81.582017 > > > > Largest 10 eigenvalues > > 176431487319.625000 > > 176431532012.467468 > > 176431562378.361359 > > 176435480628.136292 > > 176435488209.944031 > > 176435555689.747253 > > 176435563270.922424 > > 663312473823.916260 > > 663312473823.917969 > > 663312666285.928589 > > 663312666285.929810 > > > > You will never get convergence to the small eigenvalues in this way, since > the largest ones are huge. Try something like: > ./ex7.exe -f1 k.dat -f2 m.dat -eps_gen_hermitian -st_type sinvert > -eps_target 1.0 > > Jose > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110802/09e746e8/attachment.htm>
