<div dir="ltr">We could still do it. See the example at  petsc/src/vec/is/sf/tests/ex9.c<div><br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">--Junchao Zhang</div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Feb 16, 2022 at 8:47 AM Medane TCHAKOROM <<a href="mailto:medane.tchakorom@univ-fcomte.fr">medane.tchakorom@univ-fcomte.fr</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
  
    
  
  <div>
    <p>Re:</p>
    <p><br>
    </p>
    <p>It does not apply, because "<span style="color:rgb(0,0,0);font-family:"Times New Roman";font-size:medium;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">their
        communicator must be on the same set of processes" .</span></p>
    <p>In my case, I have two disjoint subcomm from PETSC_COMM_WORD with
      same number of processes.<br>
    </p>
    <p>I want to send information (Petsc Vec) from one subcomm to
      another subcomm.</p>
    <p>Thanks<br>
    </p>
    <div>On 16/02/2022 15:43, Junchao Zhang
      wrote:<br>
    </div>
    <blockquote type="cite">
      
      <div dir="ltr">See Notes at <a href="https://petsc.org/main/docs/manualpages/PetscSF/VecScatterCreate.html" target="_blank">https://petsc.org/main/docs/manualpages/PetscSF/VecScatterCreate.html</a>
        <div><br>
        </div>
        <div>Does it apply to your case?  </div>
        <div><br clear="all">
          <div>
            <div dir="ltr">
              <div dir="ltr">--Junchao Zhang</div>
            </div>
          </div>
          <br>
        </div>
      </div>
      <br>
      <div class="gmail_quote">
        <div dir="ltr" class="gmail_attr">On Wed, Feb 16, 2022 at 8:12
          AM Medane TCHAKOROM <<a href="mailto:medane.tchakorom@univ-fcomte.fr" target="_blank">medane.tchakorom@univ-fcomte.fr</a>>
          wrote:<br>
        </div>
        <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
          <div>
            <p>Re:</p>
            <p>I forgot to mention that the nodes are in differents
              communicators. Does VecScatter functionnality still
              applies ?</p>
            <p>Thanks.<br>
            </p>
            <div>On 16/02/2022 15:03, Matthew Knepley wrote:<br>
            </div>
            <blockquote type="cite">
              <div dir="ltr">
                <div dir="ltr">On Wed, Feb 16, 2022 at 8:55 AM Medane
                  TCHAKOROM <<a href="mailto:medane.tchakorom@univ-fcomte.fr" target="_blank">medane.tchakorom@univ-fcomte.fr</a>>
                  wrote:<br>
                </div>
                <div class="gmail_quote">
                  <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hello,<br>
                    <br>
                    I want to pass a Petsc Vec from one node to another
                    one. Is there any <br>
                    Petsc method for doing this<br>
                  </blockquote>
                  <div><br>
                  </div>
                  <div>You likely want the VecScatter functionality.
                    There is a discussion of this in the manual: <a href="https://petsc.org/main/docs/manual/vec/?highlight=vecscatter#sec-unstruct" target="_blank">https://petsc.org/main/docs/manual/vec/?highlight=vecscatter#sec-unstruct</a></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"> or should I use
                    MPI_Irecv and MPI_Isend for non-blocking
                    communication ?<br>
                    <br>
                    When using MPI_Isend, can i send a Petsc Vec, or
                    should I get the array <br>
                    from it, and then send it ?<br>
                    <br>
                    Thanks<br>
                    <br>
                  </blockquote>
                </div>
                <br clear="all">
                <div><br>
                </div>
                -- <br>
                <div dir="ltr">
                  <div dir="ltr">
                    <div>
                      <div dir="ltr">
                        <div>
                          <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.cse.buffalo.edu/~knepley/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br>
                            </div>
                          </div>
                        </div>
                      </div>
                    </div>
                  </div>
                </div>
              </div>
            </blockquote>
          </div>
        </blockquote>
      </div>
    </blockquote>
  </div>

</blockquote></div>