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<body class='hmmessage'><div dir='ltr'>Hi, I have been trying to solve a generalized eigenvalue problem using<br>SLEPc's EPS object. I have <span class="st">tried to parallelize my solver, so I should <br>use PETSc's mpiaij matrices instead of seqaij matrices. <br>Unfortunately, </span><span class="st"><span class="st">PETSc's </span>LU preconditioner does not support MPI matrices. <br>(this is said in the manual and if I use it with mpiaij matrices I <br>get an error message) I get the eigenvalue problem solved with <br>LU preconditioner and seqaij matrices b</span><span class="st"><span class="st">ut, I also have to use a <br>spectral transformation ( shift-invert ) to improve convergence. <br><br>But, as I mentioned before I cannot use LU preconditioner with mpiaij <br>matrices.</span> Thus, I have changed preconditioner to Hypre's BoomerAMG, <br>for example. ( which supports mpiaij matrices ) When I use this <br>combination ( BoomerAMG/shift-invert transformation/<br>Krylov-Schur solver) I get an early convergence failure after a couple <br>of iterations. I have also tried other solvers and preconditioners, <br>(Hypre's pilut, euclid, bjacobi and Jacobi-Davidson solver) but the result is <br>the same. Without any preconditioner I also get the early convergence<br>failure and without the spectral transformation convergence is<br>too slow. Any comments or suggestions?<br><br>-Heikki<br></span> </div></body>
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