<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12pt"><div><span>Barry and Jed,</span></div><div><span></span> </div><div><span>Nice to know that! Is there a corresponding function call to set RCM?</span></div><div><span></span> </div><div><span>Thanks,</span></div><div><span>Qin</span></div><div style="display: block;" class="yahoo_quoted"> <br> <br> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div dir="ltr"> <font size="2" face="Arial"> On Friday, February 14, 2014 10:20 AM, Jed Brown <jed@jedbrown.org> wrote:<br> </font> </div> <div class="y_msg_container">Qin Lu <<a href="mailto:lu_qin_2000@yahoo.com" shape="rect"
ymailto="mailto:lu_qin_2000@yahoo.com">lu_qin_2000@yahoo.com</a>> writes:<div id="yqtfd31727" class="yqt5032100984"><br clear="none"><br clear="none">> Hello,<br clear="none">> <br clear="none">> Is the RCM reordering available for ILU preconditioner in PETSc? The manual says RCM works with LU factorization, but it does not mention it for preconditioners. </div><br clear="none"><br clear="none">It works for all factorization preconditioners (ILU, ICC, LU, Cholesky).<br clear="none"><br clear="none">~/petsc/src/ksp/ksp/examples/tutorials$ ./ex2 -m 100 -n 100 -ksp_view -pc_type ilu -pc_factor_mat_ordering_type rcm<br clear="none">KSP Object: 1 MPI processes<br clear="none"> type: gmres<br clear="none"> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement<br clear="none"> GMRES: happy breakdown tolerance 1e-30<br clear="none"> maximum
iterations=10000, initial guess is zero<br clear="none"> tolerances: relative=9.80296e-07, absolute=1e-50, divergence=10000<br clear="none"> left preconditioning<br clear="none"> using PRECONDITIONED norm type for convergence test<br clear="none">PC Object: 1 MPI processes<br clear="none"> type: ilu<br clear="none"> ILU: out-of-place factorization<br clear="none"> 0 levels of fill<br clear="none"> tolerance for zero pivot 2.22045e-14<br clear="none"> using diagonal shift on blocks to prevent zero pivot [INBLOCKS]<br clear="none"> matrix ordering: rcm<br clear="none"> factor fill ratio given 1, needed 1<br clear="none"> Factored matrix follows:<br clear="none"> Mat Object: 1 MPI processes<br clear="none"> type: seqaij<br clear="none">
rows=10000, cols=10000<br clear="none"> package used to perform factorization: petsc<br clear="none"> total: nonzeros=49600, allocated nonzeros=49600<br clear="none"> total number of mallocs used during MatSetValues calls =0<br clear="none"> not using I-node routines<br clear="none"> linear system matrix = precond matrix:<br clear="none"> Mat Object: 1 MPI processes<br clear="none"> type: seqaij<br clear="none"> rows=10000, cols=10000<br clear="none"> total: nonzeros=49600, allocated nonzeros=50000<br clear="none"> total number of mallocs used during MatSetValues calls =0<br clear="none"> not using I-node routines<br clear="none">Norm of error 0.00314611 iterations 84<br><br></div> </div> </div>
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