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Hong,<br>
<br>
On 07.02.2012 17:06, Hong Zhang wrote:
<blockquote
cite="mid:CAGCphBvGdEavFWKxRzGOvAZxR2UUkkofvXd5=VaHqC=s-DLmHQ@mail.gmail.com"
type="cite">Alexander:
<div>Thanks for sending matrix data and testing code.</div>
<div>Before testing it, I have question about your code: </div>
<div>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt
0.8ex; border-left: 1px solid rgb(204, 204, 204);
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<div bgcolor="#ffffff" text="#000000"><br>
MatCreateMPIAIJ(PETSC_COMM_WORLD, PETSC_DECIDE,
PETSC_DECIDE, N, M, 12, PETSC_NULL, 12, PETSC_NULL,
&AT);<br>
<br>
MatTranspose(A,MAT_IGNORE_MATRIX,&AT);<br>
</div>
</blockquote>
<div><br>
</div>
<div>should be replaced with</div>
<div>MatTranspose(A,MAT_INITIAL_MATRIX,&AT);</div>
</div>
</div>
</blockquote>
<br>
Hm, it seems this was the reason...<br>
<br>
<blockquote
cite="mid:CAGCphBvGdEavFWKxRzGOvAZxR2UUkkofvXd5=VaHqC=s-DLmHQ@mail.gmail.com"
type="cite">
<div>
<div class="gmail_quote">
<div> </div>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt
0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">
<div bgcolor="#ffffff" text="#000000"> <br>
To compare results I use following Matlab script:<br>
<br>
Cm = A.'*B;<br>
</div>
</blockquote>
<div> ^ </div>
<div><br>
</div>
<div>Do you mean 'Cm = A'*B;'? </div>
<div>'Cm = A.'*B;' gives component-wise matrix product, not
matrix product.</div>
</div>
</div>
</blockquote>
<br>
.' operator means non-Hermitian transpose. That is what I get with
MatTranspose (in contrast with MatHermitianTranspose)<br>
component-wise matrix product would be .*<br>
<br>
<blockquote
cite="mid:CAGCphBvGdEavFWKxRzGOvAZxR2UUkkofvXd5=VaHqC=s-DLmHQ@mail.gmail.com"
type="cite">
<div>
<div class="gmail_quote">
<div><br>
</div>
<div>Hong</div>
<div><br>
</div>
<div> </div>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt
0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">
<div bgcolor="#ffffff" text="#000000"> C =
PetscBinaryRead('C.dat','complex',true);<br>
<br>
Matrix C is different depending on number of cores I use.
<br>
My PETSc is:<br>
Using Petsc Development HG revision:
876c894d95f4fa6561d0a91310ca914592527960 HG Date: Tue Jan
10 19:27:14 2012 +0100
<div>
<div class="h5"><br>
<br>
On 06.02.2012 17:13, Hong Zhang wrote:
<blockquote type="cite">MatMatMult() in petsc is not
well-tested for complex - could be buggy.
<div>Can you send us the matrices A and B in petsc
binary format for investigation?</div>
<div><br>
</div>
<div>Hong<br>
<br>
<div class="gmail_quote">On Mon, Feb 6, 2012 at
5:55 AM, Alexander Grayver <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:agrayver@gfz-potsdam.de"
target="_blank">agrayver@gfz-potsdam.de</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:
0pt 0pt 0pt 0.8ex; border-left: 1px solid
rgb(204, 204, 204); padding-left: 1ex;">Dear
PETSc team,<br>
<br>
I try to use:<br>
call
MatMatMult(A,B,MAT_INITIAL_MATRIX,PETSC_DEFAULT_DOUBLE_PRECISION,C,ierr);CHKERRQ(ierr)<br>
<br>
Where both A and B are rectangular, but A is
sparse and B is dense. Both are double complex
and distributed.<br>
The product PETSc gives me contains some
errors in some part of the matrix.<br>
I output A, B and C then computed product in
matlab.<br>
<br>
Attached you see figure plotted as:<br>
imagesc(log10(abs(C-Cm)))<br>
<br>
Where Cm -- product computed in matlab.<br>
<br>
The pattern and amplitude vary depending on
the number of cores I use. This picture is
obtained for 48 cores (I've tried 12, 64 cores
as well).<br>
<br>
Where should I look for possible explanation?<span><font
color="#888888"><br>
<br>
-- <br>
Regards,<br>
Alexander<br>
</font></span></blockquote>
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<span class="HOEnZb"><font color="#888888">
<pre cols="72">--
Regards,
Alexander</pre>
</font></span></div>
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<br>
<br>
<pre class="moz-signature" cols="72">--
Regards,
Alexander</pre>
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