<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix">I hear you though that is not what
petsc does.<br>
When I name the fields as you suggest:<br>
<blockquote>
<div>-fieldsplit_0_fieldsplit_Field_0_fields 1<br>
</div>
<div>-fieldsplit_0_fieldsplit_Field_1_fields 0<br>
</div>
</blockquote>
<div>petsc ignores it and still call the fields<br>
<blockquote>-fieldsplit_0_fieldsplit_Field_2<br>
-fieldsplit_0_fieldsplit_Field_3<br>
</blockquote>
But the automatic naming scheme is not really the issue. It
would just be nice to be able to switch the two fields.<br>
I will try to change the order in which I pass the IS to the DM
and see if I can go around the problem that way.<br>
</div>
<pre class="moz-signature" cols="72">Best,
Luc</pre>
On 03/21/2014 12:13 PM, Matthew Knepley wrote:<br>
</div>
<blockquote
cite="mid:CAMYG4GkqxaHxBtAmvZZ7tEsX6yAViyPuRLp7Y4C6Xqwgph57xA@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">On Fri, Mar 21, 2014 at 9:37 AM, Luc
Berger-Vergiat <span dir="ltr"><<a
moz-do-not-send="true" href="mailto:lb2653@columbia.edu"
target="_blank">lb2653@columbia.edu</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Is there a way to now what the new numbering is?<br>
I am assuming that in y example since there are two
fields only the numbers associated with them are 0 and
1 hence I tried:<br>
<blockquote>-fieldsplit_0_fieldsplit_Field_2_fields 1<br>
-fieldsplit_0_fieldsplit_Field_3_fields 0<br>
</blockquote>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>If its an inner fieldsplit, the numbering for options
starts over again</div>
<div><br>
</div>
<div> -fieldsplit_0_fieldsplit_Field_0_fields 1<br>
</div>
<div> -fieldsplit_0_fieldsplit_Field_1_fields 0<br>
</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div> Matt</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>
<blockquote> </blockquote>
which did not work. As mentioned earlier, the
following does not work either:<br>
<blockquote>-fieldsplit_0_fieldsplit_Field_2_fields 3<br>
-fieldsplit_0_fieldsplit_Field_3_fields 2<br>
</blockquote>
and without too much expectation I also passed the
following<br>
<blockquote>-fieldsplit_0_fieldsplit_Field_2_fields
Field_3<br>
-fieldsplit_0_fieldsplit_Field_3_fields Field_2</blockquote>
to no avail.<br>
<br>
By the way I attached the output from -ksp_view in
case I might be doing something wrong?<br>
<br>
<pre cols="72">Best,
Luc</pre>
On 03/20/2014 09:01 PM, Matthew Knepley wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">On Thu, Mar 20, 2014 at
6:20 PM, Luc Berger-Vergiat <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:lb2653@columbia.edu"
target="_blank">lb2653@columbia.edu</a>></span>
wrote:<br>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> Hi all,<br>
I am solving a four field problem using two
Schur complements. Here are the arguments
that I usually pass to PETSc to do it:<br>
<blockquote>-ksp_type gmres -pc_type
fieldsplit -pc_fieldsplit_type schur
-pc_fieldsplit_schur_factorization_type
full -pc_fieldsplit_schur_precondition
selfp -pc_fieldsplit_0_fields 2,3
-pc_fieldsplit_1_fields 0,1
-fieldsplit_0_ksp_type preonly
-fieldsplit_0_pc_type fieldsplit
-fieldsplit_0_pc_fieldsplit_type schur
-fieldsplit_0_pc_fieldsplit_schur_factorization_type
full
-fieldsplit_0_pc_fieldsplit_schur_precondition
selfp
-fieldsplit_0_fieldsplit_Field_2_fields 2
-fieldsplit_0_fieldsplit_Field_3_fields 3
-fieldsplit_0_fieldsplit_Field_2_ksp_type
preonly
-fieldsplit_0_fieldsplit_Field_2_pc_type
ilu
-fieldsplit_0_fieldsplit_Field_3_ksp_type
preonly
-fieldsplit_0_fieldsplit_Field_3_pc_type
jacobi -fieldsplit_1_ksp_type preonly
-fieldsplit_1_pc_type lu -malloc_log mlog
-log_summary time.log<br>
</blockquote>
One issue with this is that when I change
-fieldsplit_0_fieldsplit_Field_2_fields 2 to
-fieldsplit_0_fieldsplit_Field_2_fields 3 it
is ineffective, as if PETSc automatically
assign IS 2 to Field 2 even though it is not
what I want.<br>
Is there a way to pass the arguments
correctly so that PETSc goes about switching
the IS set of
-fieldsplit_0_fieldsplit_Field_2 and
-fieldsplit_0_fieldsplit_Field_3?<br>
This is crucial to me since I am using the
selfp option and the matrix associated to IS
3 is diagonal. By assigning the fields
correctly I can get an exact Schur
preconditioner and hence very fast
convergence. Right now my convergence is not
optimal because of this.<br>
</div>
</blockquote>
<div><br>
</div>
<div>I believe the inner Schur field statements
should not be using the original numbering,
but the inner numbering, after they have been
reordered.</div>
<div><br>
</div>
<div> Matt</div>
<div> </div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">Thanks!<br>
<br>
Best,<br>
Luc<br>
</div>
</blockquote>
</div>
<br>
<br clear="all">
<span class=""><font color="#888888">
<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 </font></span></div>
</div>
</blockquote>
<br>
</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
</div>
</div>
</blockquote>
<br>
</body>
</html>