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    Thanks for your kind replies. I will give a result after the test.<br>
    <br>
    <div class="moz-cite-prefix">On 2017年05月28日 19:32, Matthew Knepley
      wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CAMYG4GmC8Wx5cxGUDe5OxPQ8RDdU1TvrCGJ_Z0HjkETfEkg8vw@mail.gmail.com">
      <div dir="ltr">
        <div class="gmail_extra">
          <div class="gmail_quote">On Sun, May 28, 2017 at 1:49 AM, Dave
            May <span dir="ltr"><<a
                href="mailto:dave.mayhem23@gmail.com" target="_blank"
                moz-do-not-send="true">dave.mayhem23@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><br>
                <div class="gmail_quote">
                  <div>
                    <div class="h5">
                      <div>On Sun, 28 May 2017 at 08:31, leejearl <<a
                          href="mailto:leejearl@126.com" target="_blank"
                          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">Hi, PETSc developer:<br>
                        <br>
                             I need to create a PetscSection with a
                        struct. The struct is<br>
                        defined as follow,<br>
                        <br>
                            typedef struct<br>
                            {<br>
                               PetscReal x;<br>
                               PetscInt id;<br>
                            } testStruct;<br>
                        <br>
                            When I run the program, I got a wrong output
                        as follow,<br>
                        <br>
                            Vec Object: 1 MPI processes<br>
                           type: seq<br>
                        2.<br>
                        4.94066e-324<br>
                        2.<br>
                        4.94066e-324<br>
                        2.<br>
                        4.94066e-324<br>
                        2.<br>
                        4.94066e-324<br>
                        2.<br>
                        4.94066e-324<br>
                        2.<br>
                        4.94066e-324<br>
                        2.<br>
                        4.94066e-324<br>
                        2.<br>
                        4.94066e-324<br>
                        <br>
                        But when I defined the struct as<br>
                        <br>
                            typedef struct<br>
                            {<br>
                               PetscReal x;<br>
                               PetscReal id;<br>
                            } testStruct;<br>
                        <br>
                        The output is ok. It seems that  there is some
                        wrong with the memories<br>
                        when I define the "id" as a PetscInt type.</blockquote>
                      <div><br>
                      </div>
                    </div>
                  </div>
                  <div>Yep.</div>
                  <span class="">
                    <div><br>
                    </div>
                    <blockquote class="gmail_quote" style="margin:0 0 0
                      .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
                      <br>
                      I can not find out the reasons, and any one can
                      help me with it?</blockquote>
                    <div><br>
                    </div>
                  </span>
                  <div>The Vec object can only store quantities of type
                    PetscScalar. It cannot store PetscInt's and it
                    definitely cannot represent a mixture of PetscReal's
                    and PetscInt's.</div>
                </div>
              </div>
            </blockquote>
            <div><br>
            </div>
            <div>Dave is correct. However this usage completely misses
              the point of Section. Section is a device for storing
              indices into</div>
            <div>ANY storage, not just Vec and IS. I would manage an
              array of the structs that I allocate, and use the Section
              to index into.</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>
                <div class="gmail_quote">
                  <div><br>
                  </div>
                  <div>Thanks,</div>
                  <div> Dave</div>
                  <span class="">
                    <div><br>
                    </div>
                    <blockquote class="gmail_quote" style="margin:0 0 0
                      .8ex;border-left:1px #ccc solid;padding-left:1ex">
                      The<br>
                      source file "test.c" is attached.<br>
                      <br>
                      <br>
                      Thanks,<br>
                      <br>
                      leejearl<br>
                      <br>
                    </blockquote>
                  </span></div>
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          <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/%7Emk51/"
                  target="_blank" moz-do-not-send="true">http://www.caam.rice.edu/~mk51/</a><br>
              </div>
            </div>
          </div>
        </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
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