<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Mar 7, 2012, at 2:14 PM, Jed Brown wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div class="gmail_quote">On Wed, Mar 7, 2012 at 04:23, Lorenzo Alessio Botti <span dir="ltr"><<a href="mailto:ihabiamx@yahoo.it">ihabiamx@yahoo.it</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>Yes, my goal is to create a PETSc ghosted vector to communicate the shape function evaluations</div><div>at the interface quadrature points. </div></blockquote></div><br><div>Okay, and you need both values to solve the resulting Riemann problem redundantly with only one communication round (as opposed to designating an owner for each quadrature point, gathering from both sides, solving the Riemann problem non-redundantly, and broadcasting the result)?</div>
</blockquote></div><br><div>Yes, thanks. I think the option within brackets is achievable with the current behavior of exchange_tags...</div><div>Only not owned interface entities would know the ids of the "ghost" interfaces.</div><div>I can create a ghost vector, scatter the values and remember that I have to assemble local matrices only if the interface is not owned. </div><div>As a result I might have stashed entries in the matrix but I don't integrate redundantly over interfaces.</div><div>Is this what you meant?</div><div><br></div><div>Lorenzo</div><div><br></div></body></html>