<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Fri, Feb 16, 2018 at 11:36 AM, Danyang Su <span dir="ltr"><<a href="mailto:danyang.su@gmail.com" target="_blank">danyang.su@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 text="#000000" bgcolor="#FFFFFF">
    <p>On 18-02-15 05:57 PM, Matthew Knepley
      wrote:<br></p>
    <blockquote type="cite">
      <div dir="ltr">
        <div class="gmail_extra">
          <div class="gmail_quote">On Thu, Feb 15, 2018 at 7:40 PM,
            Danyang Su <span dir="ltr"><<a href="mailto:danyang.su@gmail.com" target="_blank">danyang.su@gmail.com</a>></span>
            wrote:<br>
            <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Matt,<br>
              <br>
              I have a question on DMPlexCreateFromCellList and
              DMPlexCreateFromFile. When use DMPlexCreateFromFile with
              Gmsh file input, it works fine and each processor gets its
              own part. However, when use DMPlexCreateFromCellList, all
              the processors have the same global mesh. To my
              understand, I should put the global mesh as input, right?</blockquote>
            <div><br>
            </div>
            <div>No. Each process should get part of the mesh in
              CreateFromCellList(), but the most common thing to do is
              to</div>
            <div>feed the whole mesh in on proc 0, and nothing in on the
              other procs.</div>
          </div>
        </div>
      </div>
    </blockquote>
    Thanks for the explanation. It works now.<br></div></blockquote><div><br></div><div>Great. Also feel free to suggest improvements, examples, or better documentation.</div><div><br></div><div>  Thanks,</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 text="#000000" bgcolor="#FFFFFF">
    Danyang<br>
    <blockquote type="cite">
      <div dir="ltr">
        <div class="gmail_extra">
          <div class="gmail_quote">
            <div><br>
            </div>
            <div>  Thanks,</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">
              Otherwise, I should use DMPlexCreateFromCellListParall<wbr>el
              instead if the input is local mesh.<br>
              <br>
              Below is the test code I use, results from method 1 is
              wrong and that from method 2 is correct. Would you please
              help to check if I did anything wrong with
              DMPlexCreateFromCellList input?<br>
              <br>
              !test with 4 processor, global num_cells = 8268, global
              num_nodes = 4250<br>
              <br>
              !correct results<br>
              <br>
               check rank            2  istart         2034 
              iend         3116<br>
               check rank            3  istart         2148 
              iend         3293<br>
               check rank            1  istart         2044 
              iend         3133<br>
               check rank            0  istart         2042 
              iend         3131<br>
              <br>
              !wrong results<br>
              <br>
                check rank            0  istart         8268 
              iend        12518<br>
                check rank            1  istart         8268 
              iend        12518<br>
                check rank            2  istart         8268 
              iend        12518<br>
                check rank            3  istart         8268 
              iend        12518<br>
              <br>
              <br>
                    !c *************    test part   
              *********************<br>
                    !c method 1: create DMPlex from cell list, same
              duplicated global meshes over all processors<br>
                    !c the input parameters num_cells, num_nodes,
              dmplex_cells, dmplex_verts are all global parameters
              (global mesh data)<br>
                    call DMPlexCreateFromCellList(Petsc<wbr>_Comm_World,ndim,num_cells,  
              &<br>
              num_nodes,num_nodes_per_cell, <wbr>     &<br>
              Petsc_True,dmplex_cells,ndim, <wbr>     &<br>
              dmplex_verts,dmda_flow%da,ierr<wbr>)<br>
                    CHKERRQ(ierr)<br>
              <br>
              <br>
                    !c method 2: create DMPlex from Gmsh file, for test
              purpose, this works fine, each processor gets its own part<br>
                    call DMPlexCreateFromFile(Petsc_Com<wbr>m_World,                     
              &<br>
              prefix(:l_prfx)//'.msh',0,    <wbr>         &<br>
                                            <wbr>  dmda_flow%da,ierr)<br>
                    CHKERRQ(ierr)<br>
              <br>
                    !c *************end of test
              part*********************<br>
              <br>
              <br>
                    distributedMesh = PETSC_NULL_OBJECT<br>
              <br>
                    !c distribute mesh over processes<br>
                    call DMPlexDistribute(dmda_flow%da,<wbr>0,PETSC_NULL_OBJECT,         
              &<br>
                                          distributedMesh,ierr)<br>
                    CHKERRQ(ierr)<br>
              <br>
                    !c destroy original global mesh after distribution<br>
                    if (distributedMesh /= PETSC_NULL_OBJECT) then<br>
                      call DMDestroy(dmda_flow%da,ierr)<br>
                      CHKERRQ(ierr)<br>
                      !c set the global mesh as distributed mesh<br>
                      dmda_flow%da = distributedMesh<br>
                    end if<br>
              <br>
                    !c get coordinates<br>
                    call DMGetCoordinatesLocal(dmda_flo<wbr>w%da,gc,ierr)<br>
                    CHKERRQ(ierr)<br>
              <br>
                    call DMGetCoordinateDM(dmda_flow%da<wbr>,cda,ierr)<br>
                    CHKERRQ(ierr)<br>
              <br>
                    call DMGetDefaultSection(cda,cs,ier<wbr>r)<br>
                    CHKERRQ(ierr)<br>
              <br>
                    call PetscSectionGetChart(cs,istart<wbr>,iend,ierr)<br>
                    CHKERRQ(ierr)<br>
              <br>
              #ifdef DEBUG<br>
                      if(info_debug > 0) then<br>
                        write(*,*) "check rank ",rank," istart
              ",istart," iend ",iend<br>
                      end if<br>
              #endif<br>
              <br>
              <br>
              Thanks and regards,<br>
              <br>
              Danyang<br>
              <br>
            </blockquote>
          </div>
          <br>
          <br clear="all"><span class="HOEnZb"><font color="#888888">
          <div><br>
          </div>
          -- <br>
          <div class="m_8969951643934544237gmail_signature" data-smartmail="gmail_signature">
            <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.caam.rice.edu/%7Emk51/" target="_blank">https://www.cse.buffalo.edu/~<wbr>knepley/</a><br>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </font></span></div>
      </div>
    </blockquote>
    <br>
  </div>

</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><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.caam.rice.edu/~mk51/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br></div></div></div></div></div>
</div></div>