On Wed, Sep 16, 2009 at 1:09 PM, Rodrigo Araujo <span dir="ltr"><<a href="mailto:rodrigowpa@gmail.com">rodrigowpa@gmail.com</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;">
Thanks for the answer,<br><br>But I have another question.<br><br>I am trying to multiply the matrices using 2 pcs, so I found the function MatMatMultNumeric_MPIDense_MPIDense, which probably could do this using the BLAS. My question is how the BLAS or the MPI splits the matrices to multiply them is separated pcs?<br>
</blockquote><div><br>Same divisions as the matrices already have id they are MPIDENSE.<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;">
<div class="gmail_quote">2009/9/16 Hong Zhang <span dir="ltr"><<a href="mailto:hzhang@mcs.anl.gov" target="_blank">hzhang@mcs.anl.gov</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div><br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I am multiplying matrices using this line of code:<br>
<br>
ierr = MatMatMult(A, B, MAT_INITIAL_MATRIX, ((PetscReal) 2.0),<br>
&C);CHKERRQ(ierr);<br>
<br>
But I need to see the source code of the file which has this function,<br>
because I´d want to see how the functions from BLAS is being used. Is that<br>
possible? If yes, could somebody tell me how.<br>
</blockquote>
<br></div>
We have implementations for different matrix data structures.<br>
You can search 'MatMatMult_'<br>
from petsc/src/ for all.<br>
BLAS is used in MatMatMultNumeric_SeqDense_SeqDense()<br>
in src/mat/impls/dense/seq/dense.c.<br>
For sparse matrices, we do not use BLAS in MatMatMult().<br><font color="#888888">
<br>
Hong</font><div><div></div><div><br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
<br>
-- <br>
Rodrigo W. Pimentel Araujo<br>
Engenharia da Computação<br>
UFPE<br>
</blockquote>
</div></div></blockquote></div><br><br clear="all"><br>-- <br>Rodrigo W. Pimentel Araujo<br>Engenharia da Computação<br>UFPE<br>
</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>