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<div class="moz-cite-prefix">On 18-02-15 05:57 PM, Matthew Knepley
wrote:<br>
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<blockquote type="cite"
cite="mid:CAMYG4GkBc5sKC6mBRmnKEayXE1vXeauESThXYUJtjsRNqqwCBg@mail.gmail.com">
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<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"
moz-do-not-send="true">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>
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</blockquote>
Thanks for the explanation. It works now.<br>
<br>
Danyang<br>
<blockquote type="cite"
cite="mid:CAMYG4GkBc5sKC6mBRmnKEayXE1vXeauESThXYUJtjsRNqqwCBg@mail.gmail.com">
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<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>
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-- <br>
<div class="gmail_signature" data-smartmail="gmail_signature">
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<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>
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<div><a href="http://www.caam.rice.edu/%7Emk51/"
target="_blank" moz-do-not-send="true">https://www.cse.buffalo.edu/~knepley/</a><br>
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