<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Fri, Mar 27, 2015 at 9:48 AM, Klaus Kaiser <span dir="ltr"><<a href="mailto:kaiser@igpm.rwth-aachen.de" target="_blank">kaiser@igpm.rwth-aachen.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hallo,<br>
<br>
I have a strange behavior in my code concerning the function MatAXPY. I create 3 different Matrices<br>
<br>
ierr = MatCreateBAIJ(PETSC_COMM_<u></u>WORLD, block_size, local_size, local_size, system_size, system_size, 0, d_nnz, 0, o_nnz,&A);<br>
ierr = MatSetOption(A,MAT_NEW_<u></u>NONZERO_ALLOCATION_ERR,PETSC_<u></u>TRUE);<br>
ierr = MatSetOption(A,MAT_KEEP_<u></u>NONZERO_PATTERN,PETSC_TRUE);<br>
ierr = MatSetOption(A,MAT_IGNORE_OFF_<u></u>PROC_ENTRIES,PETSC_TRUE);<br>
<br>
ierr = MatCreateBAIJ(PETSC_COMM_<u></u>WORLD, block_size, local_size, local_size, system_size, system_size, 0, d_nnz, 0, o_nnz,&At);<br>
ierr = MatSetOption(At,MAT_NEW_<u></u>NONZERO_ALLOCATION_ERR,PETSC_<u></u>TRUE);<br>
ierr = MatSetOption(At,MAT_KEEP_<u></u>NONZERO_PATTERN,PETSC_TRUE);<br>
ierr = MatSetOption(At,MAT_IGNORE_<u></u>OFF_PROC_ENTRIES,PETSC_TRUE);<br>
<br>
ierr = MatCreateBAIJ(PETSC_COMM_<u></u>WORLD, block_size, local_size, local_size, system_size, system_size, 0, d_nnz, 0, o_nnz,&Ah);<br>
ierr = MatSetOption(Ah,MAT_NEW_<u></u>NONZERO_ALLOCATION_ERR,PETSC_<u></u>TRUE);<br>
ierr = MatSetOption(Ah,MAT_KEEP_<u></u>NONZERO_PATTERN,PETSC_TRUE);<br>
ierr = MatSetOption(Ah,MAT_IGNORE_<u></u>OFF_PROC_ENTRIES,PETSC_TRUE);<br></blockquote><div><br></div><div>These creations are superfluous since you use MatDuplicate() below.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
and want to sum these three matrixes with different factors. First I fill the Matrix A with some values, and duplicate the structure of A to the other two matrices:<br>
<br>
MatAssemblyBegin(A,MAT_FINAL_<u></u>ASSEMBLY);<br>
MatAssemblyEnd(A,MAT_FINAL_<u></u>ASSEMBLY);<br>
MatDuplicate(A,MAT_DO_NOT_<u></u>COPY_VALUES,&Ah);<br>
MatDuplicate(A,MAT_DO_NOT_<u></u>COPY_VALUES,&At);<br>
MatAssemblyBegin(Ah,MAT_FINAL_<u></u>ASSEMBLY);<br>
MatAssemblyEnd(Ah,MAT_FINAL_<u></u>ASSEMBLY);<br>
MatAssemblyBegin(At,MAT_FINAL_<u></u>ASSEMBLY);<br>
MatAssemblyEnd(At,MAT_FINAL_<u></u>ASSEMBLY);<br></blockquote><div> <br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
After this I fill the matrices At and Ah with some other values, which are not beside the non zero structure (I also tried with just copying the Matrix A). Now after another MatAssembly</blockquote><div><br></div><div>I do not understand "no beside the nonzero structure". Do you mean that the nonzero structure is the same?</div><div><br></div><div>Can you first test with MAT_COPY_VALUES?</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> I want to add these Matrices in the form A+c*(Ah+d*At): </blockquote><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
MatAXPY(Ah,c,At,SAME_NONZERO_<u></u>PATTERN);<br>
MatAXPY(A,d,Ah,SAME_NONZERO_<u></u>PATTERN);<br>
<br>
When I run the method with mpi and one core everything works fine. Starting the same method with more cores, the sum of the matrices fails. It seems like some values are added</blockquote><div><br></div><div>Please send the full output of a failure when you use MAT_COPY_VALUES on 2 procs.</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"> correctly and many values are missed. Using DIFFERENT_NONZERO_STRUCTURE leads to the right behavior in the multi-core case, but is very slow. I checked with a viewer if all matrices have the same nonzero structure and this is the case.<br>
<br>
Does anyone know why this fails, or do I have made any wrong thoughts?<br>
<br>
I'm corrently working with a petsc version (Petsc Release Version 3.3.0, Patch 5, Sat Dec 1 15:10:41 CST 2012), I looked into the changelogs up to the current version and did not find any note about MatAXPY or MatAYPX.<br>
<br>
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Best and Thanks a lot for your help<span class="HOEnZb"><font color="#888888"><br>
<br>
Klaus<br>
<br>
</font></span></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature">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</div>
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