<div>I create 2 matrices using: </div><div><br></div><div>MatCreateSeqDense(PETSC_COMM_SELF, n, n, Ka, &A);<br></div><div>MatCreateSeqDense(PETSC_COMM_SELF, n, n, Kb, &B);</div><div><br></div><div>These matrices are 99% zeros ( 16,016,004 entries and 18660 non-zeros). They are symmetric and real. Their tri-diagonal elements are non-zero plus a few other entries.</div>
<div><br></div><div>I tried to use ex7 for the generalized eigenvalue problem:</div><div><br></div><div>./ex7.exe -f1 k.dat -f2 m.dat -eps_gen_hermitian -eps_smallest_real > x.out 2>&1</div><div><br></div><div>
without specifying an EPS and get:</div><div><br></div><div style="margin-left: 40px !important">Generalized eigenproblem stored in file.<div><br></div><div> Reading REAL matrices from binary files...</div><div> Number of iterations of the method: 500</div>
<div> Number of linear iterations of the method: 4009</div><div> Solution method: krylovschur</div><div><br></div><div> Number of requested eigenvalues: 1</div><div> Stopping condition: tol=1e-07, maxit=500</div><div> Number of converged approximate eigenpairs: 0</div>
</div><div><br></div><div>Is krylovschur inappropriate for this problem or have I set up the problem incorrectly by using
MatCreateSeqDense(...) to create the matrix input files in PETSc binary form?</div><div><br></div><div>---John </div>