<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Wed, Sep 13, 2017 at 6:14 PM, David Gross <span dir="ltr"><<a href="mailto:davegwebb10@gmail.com" target="_blank">davegwebb10@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><div><div><div>Hi Matt,<br></div>Thank you for getting back to me. Your answer confirms what I thought in terms of existing functionality. I think it shouldn't be too hard to make a copy of MatAXPY to MatAXY where it performs Xij = A*Xij*Yij (or without the A). I could then do the MatNorm of the resulting matrix to get what I need.</div><div><br></div><div>Is a MatAXY function desirable as a source contribution?</div></div></div></div></blockquote><div><br></div><div>Yes. I would prefer calling it MatPointwiseMult, since you can see it as VecPointwiseMult on a Vec obtained</div><div>from forgetting the linear operator structure of the matrix (forgetful functor).</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>I am hoping to use PETSc for performing basic vector and matrix operations on dense matrices and 1D vectors. The main uses are matmult, matmatmult and matrix additions and scaling. The application is for implementing a parallel version on an existing Pan-Reif matrix inversion algorithm.</div></div></div></blockquote><div><br></div><div>Is this Newton's method on the vector space of matrices?</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> The choice of using PETSc is mostly due to us already using it in the same program to solve sparse matrices (with MUMPS) with the goal of avoiding adding yet another package (ex ScaLAPACK/PBLAS) into the code even if other packages may be more directly oriented towards my application.<br><br></div>Regards,<br></div>Dave<br><div><div><div><div><div><br><br></div></div></div></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Sep 11, 2017 at 2:19 AM, 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 Sun, Sep 10, 2017 at 5:51 PM, David Gross <span dir="ltr"><<a href="mailto:davegwebb10@gmail.com" target="_blank">davegwebb10@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><div><div><div>Hello,<br></div>I was wondering if there was a matrix equivalent to the vecDot function (Frobenius inner product)? As far as I can tell the closest thing is MatNorm with NORM_FROBENIUS, but obviously this is acting on only one matrix.<br><br></div>If there is not a built in function, what is the best way to compute this? I am working fortran90.<br></div></div></div></blockquote><div><br></div></span><div>We do not have this. However, it would be trivial to add since we have</div><div><br></div><div> <a href="http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatAXPY.html" target="_blank">http://www.mcs.anl.gov/petsc<wbr>/petsc-current/docs/manualpage<wbr>s/Mat/MatAXPY.html</a></div><div><br></div><div>since you just replace + with * in our code. You could argue that we should have written for</div><div>a general ring, but C makes this cumbersome. Do you think you could make the change?</div><div><br></div><div>What are you using this for?</div><div><br></div><div> Thanks,</div><div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><div></div>Regards,<br></div>Dave<span class="m_674139435811179689HOEnZb"><font color="#888888"><br></font></span></div><span class="m_674139435811179689HOEnZb"><font color="#888888">
</font></span></blockquote></div><span class="m_674139435811179689HOEnZb"><font color="#888888"><br><br clear="all"><span class="HOEnZb"><font color="#888888"><div><br></div>-- <br><div class="m_674139435811179689m_848226107188727543gmail_signature"><div dir="ltr"><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><div><br></div><div><a href="http://www.caam.rice.edu/~mk51/" target="_blank">http://www.caam.rice.edu/~mk51<wbr>/</a><br></div></div></div>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><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><div><br></div><div><a href="http://www.caam.rice.edu/~mk51/" target="_blank">http://www.caam.rice.edu/~mk51/</a><br></div></div></div>
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