On Fri, Sep 24, 2010 at 4:12 PM, Randall Mackie <span dir="ltr"><<a href="mailto:rlmackie862@gmail.com">rlmackie862@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;">
I am interested in exploring whether or not the PCMG would be beneficial for my problem which I currently<br>solve using a KSP of bcgs and an ILU PC on a DA.<br><br>So, as a first step, I just wanted to see what happens if I switched my PC from ILU to PCMG using the<br>
Galerkin option.<br></blockquote><div><br></div><div>PCMG is not really a preconditioner. It is the Platonic Ideal for a family of preconditioners. Without knowledge</div><div>of the grid hierarchy, we cannot automatically determine interpolation and restriction operators (and really we</div>
<div>need to know about the discretization here as well). That is why DMMG is in PETSc. If we know you are on</div><div>a DA, we can do a reasonable job of computing these for you.</div><div><br></div><div> Thanks,</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;">So my command line options are:<br><br>mpiexec -np 1 /home/rmackie/d3fwd/V3_2_PETSc_DA_PCMG/d3fwd \<br>
-ksp_monitor_true_residual \<br> -ksp_type bcgs \<br> -pc_type mg \<br>
-pc_mg_levels 1 \<br> -pc_mg_cycles v \<br> -pc_mg_galerkin \<br> -help \<br><< EOF<br><br><br>However, I keep getting this error message:<br><br>Preconditioner (PC) Options -------------------------------------------------<br>
-pc_type <ilu>: Preconditioner (one of) none jacobi pbjacobi bjacobi sor lu shell mg<br> eisenstat ilu icc cholesky asm ksp composite redundant nn mat fieldsplit galerkin exotic openmp asa cp bfbt lsc redistribute (PCSetType)<br>
[0]PETSC ERROR: ------------------------------------------------------------------------<br>[0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range<br>[0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger<br>
[0]PETSC ERROR: or see <a href="http://www.mcs.anl.gov/petsc/petsc-as/documentation/troubleshooting.html#Signal[0]PETSC" target="_blank">http://www.mcs.anl.gov/petsc/petsc-as/documentation/troubleshooting.html#Signal[0]PETSC</a> ERROR: or try <a href="http://valgrind.org" target="_blank">http://valgrind.org</a> on GNU/linux and Apple Mac OS X to find memory corruption errors<br>
[0]PETSC ERROR: likely location of problem given in stack below<br>[0]PETSC ERROR: --------------------- Stack Frames ------------------------------------<br> Multigrid options<br>[0]PETSC ERROR: Note: The EXACT line numbers in the stack are not available,<br>
[0]PETSC ERROR: INSTEAD the line number of the start of the function<br>[0]PETSC ERROR: is given.<br>[0]PETSC ERROR: [0] PCSetFromOptions_MG line 318 src/ksp/pc/impls/mg/mg.c<br>[0]PETSC ERROR: [0] PCSetFromOptions line 166 src/ksp/pc/interface/pcset.c<br>
[0]PETSC ERROR: [0] KSPSetFromOptions line 320 src/ksp/ksp/interface/itcl.c<br>[0]PETSC ERROR: --------------------- Error Message ------------------------------------<br>[0]PETSC ERROR: Signal received!<br>[0]PETSC ERROR: ------------------------------------------------------------------------<br>
[0]PETSC ERROR: Petsc Release Version 3.1.0, Patch 4, Fri Jul 30 14:42:02 CDT 2010<br>[0]PETSC ERROR: See docs/changes/index.html for recent updates.<br>[0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.<br>
[0]PETSC ERROR: See docs/index.html for manual pages.<br>[0]PETSC ERROR: ------------------------------------------------------------------------<br>[0]PETSC ERROR: /home/rmackie/d3fwd/V3_2_PETSc_DA_PCMG/d3fwd on a linux-int named <a href="http://he999.prod.houston.nam.slb.com" target="_blank">he999.prod.houston.nam.slb.com</a> by rmackie Fri Sep 24 13:06:12 2010<br>
[0]PETSC ERROR: Libraries linked from /home/rmackie/SPARSE/PETsc/petsc-3.1-p4/linux-intel-debug/lib<br>[0]PETSC ERROR: Configure run at Fri Sep 24 13:02:26 2010<br>[0]PETSC ERROR: Configure options --with-fortran --with-fortran-kernels=1 --with-blas-lapack-dir=/opt/intel/cmkl/<a href="http://10.2.2.025/lib/em64t" target="_blank">10.2.2.025/lib/em64t</a> -with-scalar-type=complex --with-debugging=1 --with-cc=mpiicc --with-cxx=mpiicpc --with-fc=mpiifort<br>
[0]PETSC ERROR: ------------------------------------------------------------------------<br>[0]PETSC ERROR: User provided function() line 0 in unknown directory unknown file<br>application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0<br>
<br><br>I am running the latest version of Petsc. Any help on getting past this error message would be appreciated.<br><br>Randy M.<br><br>
</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>