On Thu, Jul 8, 2010 at 7:06 PM, Daniel L Crumly <span dir="ltr"><<a href="mailto:daniel.crumly@colorado.edu">daniel.crumly@colorado.edu</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hello all -<br>
<br>
Is there a recommended way to multiply a factored matrix by a vector<br>
(effectively MatMult where the matrix is a factored matrix or<br>
preconditioner)? Specifically, I would like to get take the ILU<br>
factorization of a matrix, then multiply a vector by this approximation.<br></blockquote><div><br></div><div>Do you actually want the action, or the action of the inverse? We only provide</div><div>the action of the inverse</div>
<div><br></div><div><a href="http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/Mat/MatSolve.html">http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/Mat/MatSolve.html</a></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;">
What I currently have is:<br>
<br>
ierr = PCGetType(pc, &pctype);CHKERRQ(ierr);<br>
if (strcmp(pctype, PCILU) == 0 || strcmp(pctype, PCICC) == 0) {<br>
ierr = PCFactorGetMatrix(pc, &M);CHKERRQ(ierr);<br>
ierr = MatMult(M, x, Mx);CHKERRQ(ierr);<br>
}<br>
<br>
which throws the runtime error (I'm currently using PETSc 3.0.0-p8.):<br>
<br>
[0]PETSC ERROR: --------------------- Error Message<br>
------------------------------------<br>
[0]PETSC ERROR: Object is in wrong state!<br>
[0]PETSC ERROR: Not for factored matrix!<br>
[0]PETSC ERROR:<br>
------------------------------------------------------------------------<br>
<br>
Any suggestions are greatly appreciated, thank you.<br>
<br>
Daniel "The Plaid Mentat" Crumly<br>
<a href="mailto:Daniel.Crumly@colorado.edu">Daniel.Crumly@colorado.edu</a><br>
--------<br>
I give you the desert chameleon, whose ability to blend itself into the<br>
background tells you all you need to know about the roots of ecology and the<br>
foundations of a personal identity.<br>
--Book of Diatribes from the Hayt Chronicle<br>
----Herbert, Frank. Children of Dune 28.<br>
<br>
<br>
</blockquote></div><br><br clear="all"><br>-- <br>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<br>