<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<font face="Ubuntu">Using <br>
<br>
-pc_type gamg -pc_mg_cycle_type v -pc_gamg_agg_nsmooths 1
-mg_coarse_sub_pc_factor_shift_type NONZERO -option_left
-ksp_view <br>
<br>
still produces the same error:<br>
<br>
[0]PCSetData_AGG bs=1 MM=131072<br>
[0]PETSC ERROR: --------------------- Error Message
------------------------------------<br>
[0]PETSC ERROR: Detected zero pivot in LU factorization:<br>
see <a class="moz-txt-link-freetext" href="http://www.mcs.anl.gov/petsc/documentation/faq.html#ZeroPivot">http://www.mcs.anl.gov/petsc/documentation/faq.html#ZeroPivot</a>!<br>
[0]PETSC ERROR: Zero pivot row 280 value 6.56964e-17 tolerance
2.22045e-14!<br>
[0]PETSC ERROR:
------------------------------------------------------------------------<br>
[0]PETSC ERROR: Petsc Release Version 3.3.0, Patch 3, Wed Aug 29
11:26:24 CDT 2012<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: ./hit on a named nid15363 by Unknown Fri May 24
17:06:50 2013<br>
[0]PETSC ERROR: Libraries linked from<br>
[0]PETSC ERROR: Configure run at<br>
[0]PETSC ERROR: Configure options<br>
[0]PETSC ERROR:
------------------------------------------------------------------------<br>
[0]PETSC ERROR: MatPivotCheck_none() line 583 in
src/mat/impls/aij/seq//ptmp/skelly/petsc/3.3.03/cray_interlagos_build/real/src/include/petsc-private/matimpl.h<br>
[0]PETSC ERROR: MatPivotCheck() line 602 in
src/mat/impls/aij/seq//ptmp/skelly/petsc/3.3.03/cray_interlagos_build/real/src/include/petsc-private/matimpl.h<br>
[0]PETSC ERROR: MatLUFactorNumeric_SeqAIJ() line 585 in
src/mat/impls/aij/seq/aijfact.c<br>
[0]PETSC ERROR: MatLUFactorNumeric() line 2803 in
src/mat/interface/matrix.c<br>
[0]PETSC ERROR: PCSetUp_LU() line 160 in
src/ksp/pc/impls/factor/lu/lu.c<br>
[0]PETSC ERROR: PCSetUp() line 832 in
src/ksp/pc/interface/precon.c<br>
[0]PETSC ERROR: KSPSetUp() line 278 in
src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: PCSetUpOnBlocks_BJacobi_Singleblock() line 715 in
src/ksp/pc/impls/bjacobi/bjacobi.c<br>
[0]PETSC ERROR: PCSetUpOnBlocks() line 865 in
src/ksp/pc/interface/precon.c<br>
[0]PETSC ERROR: KSPSetUpOnBlocks() line 154 in
src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: KSPSolve() line 403 in
src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: PCSetUpOnBlocks_BJacobi_Singleblock() line 715 in
src/ksp/pc/impls/bjacobi/bjacobi.c<br>
[0]PETSC ERROR: PCSetUpOnBlocks() line 865 in
src/ksp/pc/interface/precon.c<br>
[0]PETSC ERROR: KSPSetUpOnBlocks() line 154 in
src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: KSPSolve() line 403 in
src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: PCMGMCycle_Private() line 20 in
src/ksp/pc/impls/mg/mg.c<br>
[0]PETSC ERROR: PCMGMCycle_Private() line 49 in
src/ksp/pc/impls/mg/mg.c<br>
[0]PETSC ERROR: PCMGMCycle_Private() line 49 in
src/ksp/pc/impls/mg/mg.c<br>
[0]PETSC ERROR: PCMGMCycle_Private() line 49 in
src/ksp/pc/impls/mg/mg.c<br>
[0]PETSC ERROR: PCApply_MG() line 326 in src/ksp/pc/impls/mg/mg.c<br>
[0]PETSC ERROR: PCApply() line 384 in
src/ksp/pc/interface/precon.c<br>
[0]PETSC ERROR: KSPSolve_CG() line 139 in
src/ksp/ksp/impls/cg/cg.c<br>
[0]PETSC ERROR: KSPSolve() line 446 in
src/ksp/ksp/interface/itfunc.c<br>
<br>
</font>
<div class="moz-cite-prefix">On 05/24/2013 02:51 PM, Jed Brown
wrote:<br>
</div>
<blockquote cite="mid:87r4gwnj1a.fsf@mcs.anl.gov" type="cite">
<pre wrap="">Michele Rosso <a class="moz-txt-link-rfc2396E" href="mailto:mrosso@uci.edu"><mrosso@uci.edu></a> writes:
</pre>
<blockquote type="cite">
<blockquote type="cite">
<pre wrap=""> With petsc-3.4 (which you should upgrade to), use
-mg_coarse_sub_pc_factor_shift_type NONZERO
</pre>
</blockquote>
</blockquote>
<pre wrap="">
Actually, use this with petsc-3.3 also (and please upgrade to
petsc-3.4).
The option you were passing was not being used.
</pre>
</blockquote>
<br>
</body>
</html>