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<font color="#ff0000"><font color="#000000">Hi all,<br>
I am running an FEM simulation that uses Petsc as a linear
solver.<br>
I am setting up ISs and pass them to a DMShell in order to use
the FieldSplit capabilities of Petsc.<br>
<br>
When I pass the following options to Petsc:<br>
</font></font>
<blockquote>" -ksp_type gmres -pc_type fieldsplit
-pc_fieldsplit_type schur -pc_fieldsplit_schur_factorization_type
full -pc_fieldsplit_schur_precondition selfp
-pc_fieldsplit_0_fields 1,2 -pc_fieldsplit_1_fields 0
-fieldsplit_0_ksp_type preonly -fieldsplit_0_pc_type ilu
-fieldsplit_Field_0_ksp_type gmres -fieldsplit_Field_0_pc_type mg
-malloc_log mlog -log_summary time.log"<br>
</blockquote>
I get an error message:<br>
<font color="#ff0000"><br>
[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------</font><br>
[0]PETSC ERROR: <br>
[0]PETSC ERROR: Must call DMShellSetGlobalVector() or
DMShellSetCreateGlobalVector()<br>
[0]PETSC ERROR: See
<a class="moz-txt-link-freetext" href="http://http://www.mcs.anl.gov/petsc/documentation/faq.html">http://http://www.mcs.anl.gov/petsc/documentation/faq.html</a> for
trouble shooting.<br>
[0]PETSC ERROR: Petsc Development GIT revision:
v3.4.4-5071-g1163a46 GIT Date: 2014-03-26 22:20:51 -0500<br>
[0]PETSC ERROR:
/home/luc/research/feap_repo/ShearBands/parfeap-dev/feap on a
arch-linux2-c-opt named euler by luc Tue May 20 11:31:11 2014<br>
[0]PETSC ERROR: Configure options --download-cmake --download-hypre
--download-metis --download-mpich --download-parmetis
--with-debugging=no --with-share-libraries=no<br>
[0]PETSC ERROR: #1 DMCreateGlobalVector_Shell() line 245 in
/home/luc/research/petsc/src/dm/impls/shell/dmshell.c<br>
[0]PETSC ERROR: #2 DMCreateGlobalVector() line 669 in
/home/luc/research/petsc/src/dm/interface/dm.c<br>
[0]PETSC ERROR: #3 DMGetGlobalVector() line 154 in
/home/luc/research/petsc/src/dm/interface/dmget.c<br>
<br>
I am not really sure why this happens but it only happens when
-fieldsplit_Field_0_pc_type mg, with other preconditioners, I have
no problems. I attached the ksp_view in case that's any use.<br>
<pre class="moz-signature" cols="72">--
Best,
Luc</pre>
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