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Jed<br>
<br>
The problem with MatGetSubMatrix is that iscol isn't available
easily. I want to get all associated columns but according to the
man page it is not possible in Fortran.<br>
<br>
"If iscol is PETSC_NULL then all columns are obtained (not supported
in Fortran)."<br>
<br>
Is there a workaround?<br>
<br>
Tabrez<br>
<br>
On 01/14/2013 03:38 PM, Jed Brown wrote:
<blockquote
cite="mid:CAM9tzSknRJrEsZ2yAG-rjxMPemwDN6AB+_DwinV9pmpou41x8A@mail.gmail.com"
type="cite">
<div dir="ltr">On Mon, Jan 14, 2013 at 3:27 PM, Tabrez Ali <span
dir="ltr"><<a moz-do-not-send="true"
href="mailto:stali@geology.wisc.edu" target="_blank">stali@geology.wisc.edu</a>></span>
wrote:<br>
<div class="gmail_extra">
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">Hello<br>
<br>
I am solving a system of equations of the form:<br>
<br>
|A C| |u1| = |f1|<br>
|C'B| |u2| |f2|<br>
<br>
After each solve, I need to perform B*f2 before updating
f. Should I use MatGetSubMatrix/VecGetSubVector followed
by MatMult or is there something simpler.<br>
</blockquote>
<div><br>
</div>
<div style="">Yes, or let PCFIELDSPLIT do all the block
solver stuff for you.</div>
</div>
</div>
</div>
</blockquote>
<br>
<br>
<pre class="moz-signature" cols="72">--
No one trusts a model except the one who wrote it; Everyone trusts an observation except the one who made it- Harlow Shapley</pre>
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