On Mon, May 16, 2011 at 5:54 PM, Ataollah Mesgarnejad <span dir="ltr"><<a href="mailto:amesga1@tigers.lsu.edu">amesga1@tigers.lsu.edu</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;">
Dear Barry,<div><br></div><div>In that example the basis for null space is empty(only constant null space). I was wondering how would I form a Vec for example a for a 2D null space?</div><div>Specifically I'm trying to remove a null space that its span(C,x,y) in my 2D matrix that I form using DA?</div>
</blockquote><div><br></div><div>Do you mean the null space is translations in x and y? Then you give two vectors, the first with 1s in the first component,</div><div>and the second with 1s in the second component. These can be easily made using DAVecGetArrayDOF.</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;">
<div>Best,</div><div>Ata<br><br><div class="gmail_quote">On Mon, May 16, 2011 at 2:02 PM, Barry Smith <span dir="ltr"><<a href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
src/ksp/ksp/examples/tests/ex20.c<br>
<br>
Note that this is not a good example from the point of view of efficient generation of the matrix and solution of the linear system but it does demonstrate these functions<br>
<font color="#888888"><br>
Barry<br>
</font><div><div></div><div><br>
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On May 16, 2011, at 12:39 PM, Ataollah Mesgarnejad wrote:<br>
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> Dear all,<br>
><br>
> Does anyone know of any example programs that use MatNullSpaceCreate and KSPsetNullSpace routines?<br>
><br>
> Best,<br>
> Ata<br>
<br>
</div></div></blockquote></div><br><br clear="all"><br>-- <br>A. Mesgarnejad<br>PhD Student, Research Assistant<br>Mechanical Engineering Department<br>Louisiana State University<br>2203 Patrick F. Taylor Hall<br>Baton Rouge, La 70803<br>
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</blockquote></div><br><br clear="all"><br>-- <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>