On Mon, Aug 1, 2011 at 5:27 PM, John Chludzinski <span dir="ltr"><<a href="mailto:jchludzinski@gmail.com">jchludzinski@gmail.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<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>
</blockquote><div><br></div><div>Please give some justification for doing this? On the surface, it just seems perverse.</div><div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<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><font color="#888888"><div>---John </div>
</font></blockquote></div><br><br clear="all"><br>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener<br>