<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
  </head>
  <body>
    Thanks for your kind reply. It helps me very much.<br>
    <br>
    leejearl<br>
    <br>
    <div class="moz-cite-prefix">On 2017年05月29日 15:47, Dave May wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CAJ98EDqExAd=K+-kJ=a8m2mAtYCxjkdn6p5weseyBo=rcLF2Mw@mail.gmail.com">
      <div><br>
        <div class="gmail_quote">
          <div>On Mon, 29 May 2017 at 08:39, leejearl <<a
              href="mailto:leejearl@126.com" moz-do-not-send="true">leejearl@126.com</a>>
            wrote:<br>
          </div>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">
            <div> Hi, all:<br>
              I have create a IS for every cell in dmplex by the
              following steps:<br>
              1. Creating a integer array which size is matched to the
              number of cells. <br>
              2. Use the routine "ISCreateGeneral" to create a
              corresponding IS.<br>
              <br>
              Is there any routine which can create a IS for every cell
              in the dmplex directly?, </div>
          </blockquote>
          <div><br>
          </div>
          <div>I don't think so as Plex would have to somehow know what
            geom quantity to use to define the size of IS (e.g. vertex,
            cell, face, edge)</div>
          <div><br>
          </div>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">
            <div>and what is the difference between ISCopy() and
              ISDuplicate()?</div>
          </blockquote>
          <div><br>
          </div>
          <div>ISDuplicate allocates memory for a new with the same comm
            and layout as the original IS AND copies values from the
            original IS into the new one. (Note that this is slightly
            different from other duplicate functions like VecDuplicate
            which only allocate memory and does not copy values from the
            orig vec.)</div>
          <div><br>
          </div>
          <div>ISCopy does not allocate memory for the IS (passed as the
            second arg), it only performs the copy of values.</div>
          <div><br>
          </div>
          <div>Thanks </div>
          <div>  Dave </div>
          <div><br>
          </div>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">
            <div><br>
              <br>
              Thanks,<br>
              leejearl</div>
            <div><br>
              <br>
              <div class="m_8698770728479569504moz-cite-prefix">On
                2017年05月28日 19:35, Matthew Knepley wrote:<br>
              </div>
              <blockquote type="cite">
                <div>
                  <div class="gmail_extra">
                    <div class="gmail_quote">On Sun, May 28, 2017 at
                      6:02 AM, Lawrence Mitchell <span><<a
                          href="mailto:lawrence.mitchell@imperial.ac.uk"
                          target="_blank" moz-do-not-send="true">lawrence.mitchell@imperial.ac.uk</a>></span>
                      wrote:<br>
                      <blockquote class="gmail_quote" style="margin:0 0
                        0 .8ex;border-left:1px #ccc
                        solid;padding-left:1ex"><span><br>
                          <br>
                          > On 28 May 2017, at 09:16, leejearl <<a
                            href="mailto:leejearl@126.com"
                            target="_blank" moz-do-not-send="true">leejearl@126.com</a>>
                          wrote:<br>
                          ><br>
                          > Hi, Dave: I want to store a PetscInt tag
                          for every cell of the dmplex with the struct.
                          Thanks,<br>
                          <br>
                        </span>You probably want to use a DMLabel to
                        store these ids. Unless you have a different I'd
                        for every cell.</blockquote>
                      <div><br>
                      </div>
                      <div>Several things to think about:</div>
                      <div><br>
                      </div>
                      <div>1) If you want to store a tag for EVERY cell,
                        then just use an IS. Cell numberings are
                        guaranteed to be</div>
                      <div>    contiguous and start from 0.</div>
                      <div><br>
                      </div>
                      <div>2) If you want to tag only SOME cells, then
                        use a DMLabel as Lawrence suggests. This uses
                        hash tables</div>
                      <div>    for fast construction, and sorted lists
                        for fast search and retrieval.</div>
                      <div><br>
                      </div>
                      <div>3) If you want to store a VARIABLE number of
                        data items per cell, then use a Section and an
                        array that you allocate.</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"><span
                          class="m_8698770728479569504HOEnZb"><font
                            color="#888888"><br>
                            Lawrence<br>
                          </font></span></blockquote>
                    </div>
                    <br>
                    <br clear="all">
                    <div><br>
                    </div>
                    -- <br>
                    <div class="m_8698770728479569504gmail_signature"
                      data-smartmail="gmail_signature">
                      <div>
                        <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/%7Emk51/"
                            target="_blank" moz-do-not-send="true">http://www.caam.rice.edu/~mk51/</a><br>
                        </div>
                      </div>
                    </div>
                  </div>
                </div>
              </blockquote>
              <br>
            </div>
            <div>
              <pre class="m_8698770728479569504moz-signature" cols="72">-- 
李季
西北工业大学航空学院流体力学系
Phone: 17792092487
QQ: 188524324
</pre>
            </div>
          </blockquote>
        </div>
      </div>
    </blockquote>
    <br>
    <pre class="moz-signature" cols="72">-- 
李季
西北工业大学航空学院流体力学系
Phone: 17792092487
QQ: 188524324
</pre>
  </body>
</html>