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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">I have recently started using petsc and have little experience with parallel programming.<br>

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I am having problem with the following section of my code:<br>

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        KSPGetPC(ksp,&pc);<br>

        PCSetType(pc,PCCHOLESKY);<br>

        PCFactorSetMatSolverPackage(pc,MATSOLVERMUMPS);<br>

        PCFactorSetUpMatSolverPackage(pc);<br>

        PCFactorGetMatrix(pc,&L);<br>

        MatMumpsSetIcntl(L,7,2);<br>

        MatMumpsSetCntl(L,1,0.0);<br>

        MatMumpsSetIcntl(L,33,1);<br>

        KSPSetUp(ksp);<br>

        KSPSolve(ksp, y, alpha);<br>

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        VecDot(y, alpha, &sigma);<br>

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when I run it using a single processor (mpiexec -np 1 ....) I get the correct answer, when I run using 2 processors I get sigma = 4*sigma and so on.

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How can I solve this problem??<br>

<br>

ZL<br>

<br>

<br>

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