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
