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Dear all,<br>
<br>
<br>
Max may be correct, but I encounter the same problem as Aron.
Neither PCILU nor PCICC work in parallel for me. Here is the
message I get:<br>
<br>
<tt>[0]PETSC ERROR: --------------------- Error Message
------------------------------------<br>
[0]PETSC ERROR: No support for this operation for this object
type!<br>
[0]PETSC ERROR: Matrix format mpiaij does not have a built-in
PETSc ICC!<br>
[0]PETSC ERROR:
------------------------------------------------------------------------<br>
[0]PETSC ERROR: Petsc Release Version 3.2.0, Patch 6, Wed Jan 11
09:28:45 CST 2012<br>
[0]PETSC ERROR: See docs/changes/index.html for recent updates.<br>
[0]PETSC ERROR: See docs/faq.html for hints about trouble
shooting.<br>
[0]PETSC ERROR: See docs/index.html for manual pages.<br>
<br>
</tt>Portion of the code which I use to set the solver contents
follows (I am aiming at CG+ICC combination):<br>
<br>
<tt>/* Create KPS content */<br>
KSPCreate(PETSC_COMM_WORLD, &ksp);<br>
KSPSetType(ksp ,KSPCG);<br>
<br>
/* Set operators */<br>
KSPSetOperators(ksp, A, A, DIFFERENT_NONZERO_PATTERN);<br>
<br>
/* Linear solver defaults (can be ove-ridden) */<br>
KSPGetPC(ksp, &pc);<br>
PCSetType(pc, PCICC);<br>
KSPSetTolerances(ksp, 1.e-5, PETSC_DEFAULT, PETSC_DEFAULT,
PETSC_DEFAULT);<br>
<br>
/* Run-time options (over-rides above) */<br>
KSPSetFromOptions(ksp);</tt><br>
<br>
What is going wrong here?<br>
<br>
<br>
Kind regards,<br>
<br>
<br>
Bojan<br>
<br>
<br>
On 2/26/2012 6:17 PM, Matthew Knepley wrote:
<blockquote
cite="mid:CAMYG4GnK-s+X=OJk596PsS3HBmoNxBOHLmCA2y4hf-rjOc2fCA@mail.gmail.com"
type="cite">On Sun, Feb 26, 2012 at 10:48 AM, Max Rudolph <span
dir="ltr"><<a moz-do-not-send="true"
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
moz-do-not-send="true"
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 moz-do-not-send="true"
href="http://www.mcs.anl.gov/petsc/documentation/linearsolvertable.html"
target="_blank">http://www.mcs.anl.gov/petsc/documentation/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>
</blockquote>
<br>
<br>
<div class="moz-signature">-- <br>
<img src="cid:part1.04070409.05000708@psi.ch" border="0"></div>
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