On Fri, Sep 18, 2009 at 8:48 AM, Hong Zhang <span dir="ltr"><<a href="mailto:hzhang@mcs.anl.gov">hzhang@mcs.anl.gov</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
Should we create a new matrix type, say hbaij,<br>
for operations of Hermitian matrices?<font color="#888888"><br></font></blockquote><div><br>No, it should be a minor perturbation.<br><br> Matt<br> </div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<font color="#888888">
Hong</font><div><div></div><div class="h5"><br>
<br>
On Fri, 18 Sep 2009, Matthew Knepley wrote:<br>
<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
On Fri, Sep 18, 2009 at 7:32 AM, Niall Moran <<a href="mailto:nmoran@thphys.nuim.ie" target="_blank">nmoran@thphys.nuim.ie</a>> wrote:<br>
<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Matthew Knepley wrote:<br>
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<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
On Thu, Sep 17, 2009 at 12:44 PM, Niall Moran <<a href="mailto:nmoran@thphys.nuim.ie" target="_blank">nmoran@thphys.nuim.ie</a><mailto:<br>
<a href="mailto:nmoran@thphys.nuim.ie" target="_blank">nmoran@thphys.nuim.ie</a>>> wrote:<br>
<br>
Hi,<br>
<br>
I am just wondering if anything has changed on the status of this<br>
feature. Would be great to be able to perform matrix vector<br>
multiplications on complex Hermitian matrices by only providing<br>
one half of the matrix.<br>
<br>
<br>
It is not curently in the todo list since we have only had one request. It<br>
seems like it would just take being careful about the<br>
complex case for SBAIJ if you would like the try the implementation. We<br>
can answer questions.<br>
<br>
Thanks for you rapid response. I would be interested in attempting to<br>
</blockquote>
implement this for MPIAIJ if it would not be too involved. Would you be able<br>
to sketch a rough outline of what this would involve? Would I need to just<br>
modify the MatMult_MPIAIJ function or would I need to modify the creation of<br>
the scatterers in MatAssemblyBegin_MPIAIJ?<br>
<br>
Could anyone suggest some documentation that describes how the matrix<br>
vector multiplication works in petsc for MPIAIJ typed matrices?<br>
<br>
Does matrix vector multiplication with just the upper half work for real<br>
symmetric matrices?<br>
<br>
</blockquote>
<br>
1) Understand the SBAIJ implementation. This is used for real symmetric<br>
matrices<br>
<br>
2) In the places where the lower triangle is retrieved, add a complex<br>
conjugation.<br>
<br>
Matt<br>
<br>
<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Regards,<br>
<br>
Niall.<br>
<br>
</blockquote>
-- <br>
What most experimenters take for granted before they begin their experiments<br>
is infinitely more interesting than any results to which their experiments<br>
lead.<br>
-- Norbert Wiener<br>
<br>
</blockquote>
</div></div></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>