[petsc-users] How can I get the global integer ids in a label?

leejearl leejearl at mail.nwpu.edu.cn
Thu Dec 6 20:28:16 CST 2018


Hi Matt:	My mesh file is "*.exo". Can it works
fine?        Thanks.leejearl
On Thu, 2018-12-06 at 21:20 -0500, Matthew Knepley wrote:
> On Thu, Dec 6, 2018 at 9:08 PM leejearl <leejearl at mail.nwpu.edu.cn>
> wrote:
> > Hi, Matt:
> > 	Is the code in following page?
> > 
> > 	/petsc-master/src/snes/examples/tutorials/ex12.c.html
> 
> 
https://www.mcs.anl.gov/petsc/petsc-current/src/snes/examples/tutorials/ex12.c.html
> 
>   Matt 
> >       Thanks
> > leejearl
> > 
> > On Thu, 2018-12-06 at 20:26 -0500, Matthew Knepley wrote:
> > > On Thu, Dec 6, 2018 at 8:06 PM leejearl <
> > > leejearl at mail.nwpu.edu.cn> wrote:
> > > > Hi Matt:
> > > > 	Thank you for your helps. I want to implement the
> > > > periodic boundary in dmplex. For a cell or face, the donor cell
> > > > or face might be not distributed in the same local dm. Maybe I
> > > > should ask that how
> > > > can I implement the topology of the periodic boundary in
> > > > demplex.
> > > 
> > > Plex directly encodes a periodic topology. For example, with a
> > > circle, each vertex is connectedto two neighbors. There are
> > > example with periodic boundary conditions like SNES ex12.
> > >  Thanks,
> > >     Matt 
> > > >         Thanks again for your kind reply.
> > > > 
> > > > leejearl
> > > > On Thu, 2018-12-06 at 12:02 -0500, Matthew Knepl
> > > > > On Thu, Dec 6, 2018 at 9:47 AM leejearl via petsc-users <
> > > > > petsc-users at mcs.anl.gov> wrote:
> > > > > > Hi, Petsc developer:
> > > > > > 
> > > > > >         I have a problem for helps. 
> > > > > > 
> > > > > >         There is a dmplex object, and I have distribute it
> > > > > > use the
> > > > > > 
> > > > > > routine DMPlexDistribute(). Then, I want to get the global
> > > > > > integer ids
> > > > > > 
> > > > > > in the label "Face Sets". The code is as follow,
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > >      ierr = DMGetLabelIdIS(dm, "Face Sets",
> > > > > > &bcIdIS);CHKERRQ(ierr);
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > The values of bcIdIs are the local integer ids. How can I
> > > > > > get the
> > > > > > 
> > > > > > global integer ids.
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > The problem also can be described as follow. The global ids
> > > > > > might look
> > > > > > 
> > > > > > likes
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > IS Object: 1 MPI processes
> > > > > > 
> > > > > >   type: general
> > > > > > 
> > > > > > Number of indices in set 4
> > > > > > 
> > > > > > 0 1
> > > > > > 
> > > > > > 1 4
> > > > > > 
> > > > > > 2 3
> > > > > > 
> > > > > > 3 2
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > But after the dm is distributed, I can only get the local
> > > > > > ids as follow
> > > > > > 
> > > > > > using the routine "DMGetLabelIdIS" 
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > IS Object: 1 MPI processes
> > > > > > 
> > > > > >   type: general
> > > > > > 
> > > > > > [0] Number of indices in set 3
> > > > > > 
> > > > > > [0] 0 1
> > > > > > 
> > > > > > [0] 1 2
> > > > > > 
> > > > > > [0] 2 4
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > How can I get the global integer ids in a label after the
> > > > > > dm is
> > > > > > 
> > > > > > distributed?
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > Any helps are appreciate! 
> > > > > 
> > > > > You can make a conversion from local point numbers to global
> > > > > point numbers using
> > > > >   
> > > > > https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/DMPLEX/DMPlexCreatePointNumbering.html
> > > > > You could even make a replacement DMLabel with the global
> > > > > point numbers, but I think the win would be smallor
> > > > > nonexistent for most cases.
> > > > >   Thanks,
> > > > >     Matt 
> > > > > > Thanks
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > leejearl
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > 
> > > > > 
> > > 
> > > 
> 
> 
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