[petsc-users] markers

[Aldo Bonfiglioli]

Dear all,

it is unclear to me what is being flagged with the "marker" flag when a 
mesh is created using DMPlexCreate.

The 2D triangular mesh pictured in the enclosed pdf has the following 
features:

> DM Object: 2D plex 1 MPI process
> type: plex
> 2D plex in 2 dimensions:
> Number of 0-cells per rank: 12
> Number of 1-cells per rank: 23
> Number of 2-cells per rank: 12
> Labels:
> celltype: 3 strata with value/size (0 (12), 1 (23), 3 (12))
> depth: 3 strata with value/size (0 (12), 1 (23), 2 (12))
> marker: 1 strata with value/size (1 (20))
> Face Sets: 4 strata with value/size (1 (3), 2 (2), 3 (3), 4 (2))
>
i.e 12 gridpoints, 23 edges and 12 triangular cells.

When I call DMGetStratumSize at stratum 0 to 2, this is what I get.

> CreateSectionAlternate DMGetStratumSize found0  'marker' points @ 
> depth0  on PE#0
> CreateSectionAlternate DMGetStratumSize found20  'marker' points @ 
> depth1  on PE#0
> CreateSectionAlternate DMGetStratumSize found0  'marker' points @ 
> depth2  on PE#0
>
Is the marker flagging boundary edges or boundary vertices (nodes) ? In 
any case, why are there 20, instead of 10?

Finally: I believe face sets refers to boundary faces, where each side 
of the square domain has been given a different flag.

How do I access the face sets information ?

Thanks,

Aldo


-- 
Dr. Aldo Bonfiglioli
Associate professor of Fluid Machines
Scuola di Ingegneria
Universita' della Basilicata
V.le dell'Ateneo lucano, 10 85100 Potenza ITALY
tel:+39.0971.205203 fax:+39.0971.205215
web:https://urldefense.us/v3/__http://docenti.unibas.it/site/home/docente.html?m=002423__;!!G_uCfscf7eWS!c6_YYKL6k6FdMvXiZuhIJ2t5rbgB45aqicDR0WpLsZSgrs7NO0SMggi_L8KB2ZKd-w8JlcGQJTFm-uotq1RhZRDxD575sfToW2A$ 
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