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    <div class="moz-cite-prefix">Hi,<br>
      <br>
      Yes, a PetscSFMoveRoots() wrapper would be greatly appreciated,
      especially since we want to ultimately wrap and access this via
      petsc4py.<br>
      <br>
      Many thanks<br>
      Michael<br>
      <br>
      <br>
      On 12/11/13 17:02, Matthew Knepley wrote:<br>
    </div>
    <blockquote
cite="mid:CAMYG4GktnquSbOgKQKh+Hx-M+nAJbmZ_qzLeE5YJi92==-6-8g@mail.gmail.com"
      type="cite">
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      <div dir="ltr">On Tue, Nov 12, 2013 at 9:59 AM, Jed Brown <span
          dir="ltr"><<a moz-do-not-send="true"
            href="mailto:jedbrown@mcs.anl.gov" target="_blank">jedbrown@mcs.anl.gov</a>></span>
        wrote:<br>
        <div class="gmail_extra">
          <div class="gmail_quote">
            <blockquote class="gmail_quote" style="margin:0 0 0
              .8ex;border-left:1px #ccc solid;padding-left:1ex">
              <div class="im">Michael Lange <<a
                  moz-do-not-send="true"
                  href="mailto:michael.lange@imperial.ac.uk">michael.lange@imperial.ac.uk</a>>
                writes:<br>
                <br>
                > Hi Matt,<br>
                ><br>
                > Thanks for the clarification, this does make sense.
                I have achieved the<br>
                > local DoF ordering I want by only permuting the
                offsets in the created<br>
                > section. However, I am now trying to extract the
                according halo exchange<br>
                > information from the associated PetscSF object and,
                although the local<br>
                > leafs have been renumbered according to my
                permutation, the roots they<br>
                > are connected to have not been updated. Is there an
                easy way to update<br>
                > the roots or re-initialise the PetscSF from the
                reordered section?<br>
                <br>
              </div>
              You can SFBcast the new root numbers and create a new SF.<br>
              <br>
              Since this is a somewhat common operation that can be
              optimized by the<br>
              SF implementation, it may make sense to provide
              PetscSFMoveRoots() or<br>
              some such.<br>
            </blockquote>
          </div>
          <br>
          I already do this in DMPlexPermute(). We can abstract the code
          out.</div>
        <div class="gmail_extra"><br>
        </div>
        <div class="gmail_extra">   Matt<br clear="all">
          <div><br>
          </div>
          -- <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
        </div>
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    <br>
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