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I already use petsc-dev and DMComposite.<br>
<br>
I call PCSetDM and it works.<br>
<br>
Thanks,<br>
Loic<br>
<br>
On 24/02/2011 11:09, Jed Brown wrote:
<blockquote
cite="mid:AANLkTimypEqJSkMyx-SU3eMZxgpeEQU1E2ptsNuP=5A-@mail.gmail.com"
type="cite">
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<div>On Thu, Feb 24, 2011 at 10:56, gouarin <span><<a
moz-do-not-send="true"
href="mailto:loic.gouarin@math.u-psud.fr">loic.gouarin@math.u-psud.fr</a>></span>
wrote:<br>
<blockquote>
<div>I set block size to 3 for my matrix but I'm not sure that
I can use it because I don't have the same number of points
for each field. I don't hnow how petsc defines the blocks.<br>
<br>
How can I use again fieldsplit for the preconditioner ?</div>
</blockquote>
</div>
<br>
<div>It is worth switching to petsc-dev for this:</div>
<div><br>
</div>
<div>1. Use DMComposite to "glue" the velocity and pressure DAs
together.</div>
<div><br>
</div>
<div>2. Call PCSetDM (or the higher level KSPSetDM, SNESSetDM, or
TSSetDM as appropriate) and pass in the DMComposite.</div>
<div><br>
</div>
<div>Now when you -pc_type fieldsplit, it will automatically pick
up the fields from the DMComposite (in the order they were
registered). That would give you two splits in this case.</div>
<div><br>
</div>
<div>You can use DMComposite with petsc-3.1, but you have to
create index sets yourself and call PCFieldSplitSetIS().</div>
</blockquote>
<br>
<br>
<pre class="moz-signature" cols="72">--
Loic Gouarin
Laboratoire de Mathématiques
Université Paris-Sud
Bâtiment 425
91405 Orsay Cedex
France
Tel: (+33) 1 69 15 60 14
Fax: (+33) 1 69 15 67 18</pre>
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