<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Wed, Jul 30, 2014 at 3:59 PM, Qin Lu <span dir="ltr"><<a href="mailto:lu_qin_2000@yahoo.com" target="_blank">lu_qin_2000@yahoo.com</a>></span> wrote:<br>
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<div>Renumbering row will make an unknown not associate with its row (equation), will this affect the solver performance? For example, will the infill pattern change in ILU factorization?</div></div></div></blockquote><div>
<br></div><div>1) If you are doing parallel LU, all those packages (MUMPS, SuperLU) reorder anyway</div><div><br></div><div>2) If you are doing LU on a domain, you already have a contiguous order</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><div style="color:#000;background-color:#fff;font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12pt">
<div><span style="font-size:12pt"> </span></div><div>Thanks,</div><div>Qin </div><div><br></div> <div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12pt"> <div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12pt">
<div dir="ltr"> <div style="margin:5px 0px;padding:0px;border:1px solid rgb(204,204,204);min-height:0px;line-height:0;font-size:0px" readonly></div> <font face="Arial"> <b><span style="font-weight:bold">From:</span></b> Matthew
Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>><br> <b><span style="font-weight:bold">To:</span></b> Qin Lu <<a href="mailto:lu_qin_2000@yahoo.com" target="_blank">lu_qin_2000@yahoo.com</a>> <br>
<b><span style="font-weight:bold">Cc:</span></b> Barry Smith <<a href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>>; petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>> <br>
<b><span style="font-weight:bold">Sent:</span></b> Wednesday, July 30, 2014 3:50 PM<br> <b><span style="font-weight:bold">Subject:</span></b> Re: [petsc-users] Partition of parallel AIJ sparce matrix<br> </font> </div> <div>
<br><div><div><div dir="ltr"><div><div>On Wed, Jul 30, 2014 at 3:30 PM, Qin Lu <span dir="ltr"><<a href="mailto:lu_qin_2000@yahoo.com" shape="rect" rel="nofollow" target="_blank">lu_qin_2000@yahoo.com</a>></span> wrote:<br clear="none">
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<div>In the context of domain decompostion, if the unknowns are ordered (to reduce the number of infills, for instance) in the way that each subdomain may not own consecutive unknown index, does this mean the partition of the domain will be different from the partition of the matrix? </div>
<div> </div><div>For example, if subdomain 1 (assigned to process 1) owns unknowns 1 and 3 (associated with equation 1 and 3), subdomain 2 (assigned to process 2) owns unknowns 2 and 4 (associated with equation 2 and 4) , how can I make each process own consecutive rows?</div>
</div></blockquote><div><br clear="none"></div><div>You renumber the rows once they are partitioned.</div><div><br clear="none"></div><div> Matt</div><div><br><br></div><div><div> </div></div><blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid">
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</div><div style="color:rgb(0,0,0);font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12pt;background-color:rgb(255,255,255)"><div><div>Thanks,</div><div>Qin</div><div><br clear="none">
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</div><div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12pt"><div> <div dir="ltr"> <div style="margin:5px 0px;padding:0px;border:1px solid rgb(204,204,204);line-height:0;font-size:0px;min-height:0px">
</div> <font face="Arial"> <b><span style="font-weight:bold">From:</span></b> Barry Smith <<a href="mailto:bsmith@mcs.anl.gov" shape="rect" rel="nofollow" target="_blank">bsmith@mcs.anl.gov</a>><br clear="none"> <b><span style="font-weight:bold">To:</span></b> Qin Lu <<a href="mailto:lu_qin_2000@yahoo.com" shape="rect" rel="nofollow" target="_blank">lu_qin_2000@yahoo.com</a>> <br clear="none">
<b><span style="font-weight:bold">Cc:</span></b> petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" shape="rect" rel="nofollow" target="_blank">petsc-users@mcs.anl.gov</a>> <br clear="none"> <b><span style="font-weight:bold">Sent:</span></b> Wednesday, July 30, 2014 2:49 PM<br clear="none">
<b><span style="font-weight:bold">Subject:</span></b> Re: [petsc-users] Partition of parallel AIJ sparce matrix<br clear="none"> </font> </div> </div><div><div><br clear="none"><br clear="none">On Jul 30, 2014, at 11:08 AM, Qin Lu <<a href="mailto:lu_qin_2000@yahoo.com" shape="rect" rel="nofollow" target="_blank">lu_qin_2000@yahoo.com</a>> wrote:<br clear="none">
<br clear="none">> Hello,<br clear="none">> <br clear="none">> Does a process have to own consecutive rows of the matrix? For example, suppose the global AIJ is 4x4, partitioned by 2 processes. Does process 1 have to own rows 1 and 2, process 2 own rows 3 and 4?<br clear="none">
<br clear="none"> Yes<br clear="none"><br clear="none">> Or process1 may own rows 1 and 3, and process 2 own row 2 and 4?<br clear="none"><br clear="none"> However, the numbering of degrees of freedom is arbitrary. Just renumber you degrees of freedom so the first set is on process 0, the next on process 1 etc.<br clear="none">
<br clear="none"> Barry</div><div><div><br clear="none"><br clear="none">> <br clear="none">> Thanks a lot for your help!<br clear="none">> <br clear="none">> Regards,<br clear="none">> Qin </div><br clear="none">
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<br clear="none"><br clear="none"></div><span class="HOEnZb"><font color="#888888"> </font></span></div><span class="HOEnZb"><font color="#888888"> </font></span></div><span class="HOEnZb"><font color="#888888"> </font></span></div>
</blockquote></div><span class="HOEnZb"><font color="#888888"><br clear="none"><br clear="all"><div><br clear="none"></div>-- <br clear="none">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br clear="none">
-- Norbert Wiener
</font></span></div></div></div></div><br><br></div> </div> </div> </div></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
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