On Sun, Feb 26, 2012 at 10:48 AM, Max Rudolph <span dir="ltr"><<a href="mailto:maxwellr@gmail.com">maxwellr@gmail.com</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">
MPIAIJ and SEQQIJ matrices are subtypes of the AIJ matrix type. Looking at that table, you should be able to use any of the PCs that supports AIJ and has an X under 'parallel'. </blockquote><div><br></div><div>Max is correct. For instance, the most popular general purpose parallel solver is ASM (Additive Schwarz Method), which then</div>
<div>has a sequential subsolver for each block, which defaults to ILU.</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">
<span class="HOEnZb"><font color="#888888"><div>Max</div></font></span><div class="HOEnZb"><div class="h5"><div><br>
<br><div class="gmail_quote">On Sun, Feb 26, 2012 at 8:16 AM, Aron Roland <span dir="ltr"><<a href="mailto:aaronroland@gmx.de" target="_blank">aaronroland@gmx.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Dear All,<br>
<br>
I hope somebody can help us on this or give at least some clearance.<br>
<br>
We have just included PETSc as an solver for our sparse matrix evolving from an unstructured mesh advection scheme.<br>
<br>
The problem is that we are using the mpiaij matrix type, since our matrix is naturally sparse. However it seems that PETSc has no PC for this, except the PCSOR, which showed to be not very effective for our problem.<br>
<br>
All others give the error msg. of the mail subject, where XXX are the different PC tried.<br>
<br>
The manual is a bit diffuse on this e.g.<br>
<br>
<a href="http://www.mcs.anl.gov/petsc/documentation/linearsolvertable.html" target="_blank">http://www.mcs.anl.gov/petsc/<u></u>documentation/<u></u>linearsolvertable.html</a><br>
<br>
it is claimed that certain PC's are running on aij matrices ... but these are to be defined either as seq. or parallel (mpiaij) matrices. Moreover in the above mentioned list are two columns parallel/seriel, what is the intention of parallel capability when not applicable to matrices stored within the parallel mpiaij framework.<br>
<br>
I guess we just not understanding the concept or have some other difficulties of understanding of all this.<br>
<br>
Any comments help is welcome<span><font color="#888888"><br>
<br>
Aron<br>
</font></span></blockquote></div><br></div>
</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <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>