Topology computation for mixed topology #2994
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…lfinx into chris/topology-nightmare
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| topology = create_topology(MPI.COMM_SELF, [CellType.prism], cells, orig_index, ghost_owners, boundary_vertices) | ||
| assert len(topology.entity_types[2]) == 2 | ||
| assert CellType.triangle == entity_types[2][1] |
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What determines the order of entity_types[d]? Is it always quads then triangles? Or will this fail if the implementation changes? I couldn't find anything about the order in the docs
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At the moment, the facet order is determined in the constructor of Topology, which effectively does a sort, so quad(-4) appears before triangle(3). This could be changed, and the test would then fail, yes.
The cell order, however, is arbitrary, and depends on the user input.
So, what is the best solution? Maybe I should change the test, so it doesn't assume anything about the order?
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I think it would probably be better to avoid making the assumption in the test
| topology.create_entities(2) | ||
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| # Tet -> quad | ||
| assert topology.connectivity((3, 0), (2, 0)) is None |
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To get the connectivity between particular entity types, it looks like the user needs to first determine what cell type corresponds to what index in entity_types[d]. Would it be better if the pair had a CellType rather than an entity type index?
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That's true. I am not sure if it is better, but we could try it out. Maybe in another branch?
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I think getting the cell type index as in the (updated) test is OK
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| // Get vertices from cell | ||
| auto vertices = cells.links(c); | ||
| auto cell_type = std::get<0>(cell_lists[k]); |
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I quite like structured binding in these cases i.e. auto [cell_type, cells, cell_index_map] = cell_lists[k];
| @@ -34,27 +34,30 @@ class Topology; | |||
| /// @param[in] comm MPI Communicator | |||
| /// @param[in] topology Mesh topology | |||
| /// @param[in] dim The dimension of the entities to create | |||
| /// @param[in] index Index of entity in dimension `dim` | |||
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Maybe refer to entity_types for clarity?
Build the correct entity-entity connectivity maps for mixed topology.
Now that facets and cells can have multiple types, we need to adjust the computation algorithm.
All facets of the same type need to be computed at the same time, so all cells which contain them need to be worked on together.
This updates
compute_entities()andcompute_connectivity()to account for this.Including some tests on a simple topology (2 tet + 1 prism + 1 hex)