<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Tue, Jul 7, 2015 at 3:36 PM, Bikash Kanungo <span dir="ltr"><<a href="mailto:bikash@umich.edu" target="_blank">bikash@umich.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div>Hi Matthew,<br><br></div>The entries to the last few rows of my matrix has non-local contributions from a large number of processors. Since the matrix is symmetric, I need not set the non-local entries in the last few rows as they are equal to their transpose entries, which on the other hand are stored as local entries in their respective processors.<br></div></div></div></blockquote><div><br></div><div>This is really a sparse matrix with a low rank update. It is much easier to handle it this way. There are explicit formulae for the inverse</div><div>in terms of the inverse of the two parts (Sherman-Morrison-Woodbury), and other operations can be similarly simplified. We might not</div><div>have all the support now, but pressing forward on this front is likely to be much more fruitful.</div><div><br></div><div> Thanks,</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 dir="ltr"><div><div></div>Thanks,<br></div>Bikash <br></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Jul 7, 2015 at 4:25 PM, Matthew Knepley <span dir="ltr"><<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><span>On Tue, Jul 7, 2015 at 3:22 PM, Bikash Kanungo <span dir="ltr"><<a href="mailto:bikash@umich.edu" target="_blank">bikash@umich.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div>Hi,<br><br></div>Is there a way to ignore the lower (or upper) triangular entries in an MATMPIAIJ matrix when I know my matrix is symmetric? I can see a MAT_SYMMETRIC option in MatSetOption, but I don't think it ignores any lower (or upper) triangular entry. <br></div></div></div></div></blockquote><div><br></div></span><div>Why do you want this?</div><span><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div></div>I cannot use MATMPISBAIJ due to MatMatMult incompatibility with MATMPIAIJ. <br></div></div></div></blockquote><div><br></div></span><div>This is the only way. MatMatMult() is quite complex and there is no real advantage to ignoring</div><div>the entries, so we have not implemented it here.</div><div><br></div><div> Matt</div><span><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div></div>Thanks,<br></div>Bikash<span><font color="#888888"><br clear="all"><div><div><div><div><div><br>-- <br><div><div dir="ltr"><div><div><div><div><font color="#666666">Bikash S. Kanungo<br></font></div><font color="#666666">PhD Student<br></font></div><font color="#666666">Computational Materials Physics Group<br></font></div><font color="#666666">Mechanical Engineering <br></font></div><font color="#666666">University of Michigan<br><br></font></div></div>
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</blockquote></span></div><span><font color="#888888"><br><br clear="all"><span class="HOEnZb"><font color="#888888"><div><br></div>-- <br><div>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>
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</font></span></blockquote></div><span class="HOEnZb"><font color="#888888"><br><br clear="all"><br>-- <br><div><div dir="ltr"><div><div><div><div><font color="#666666">Bikash S. Kanungo<br></font></div><font color="#666666">PhD Student<br></font></div><font color="#666666">Computational Materials Physics Group<br></font></div><font color="#666666">Mechanical Engineering <br></font></div><font color="#666666">University of Michigan<br><br></font></div></div>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature">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>
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