xref: /petsc/include/petscdmtypes.h (revision 390e1bf27627d887df99a9f4d0d0ad68037f55ec)
1 #if !defined(_PETSCDMTYPES_H)
2 #define _PETSCDMTYPES_H
3 
4 /*S
5      DM - Abstract PETSc object that manages an abstract grid object and its interactions with the algebraic solvers
6 
7    Level: intermediate
8 
9   Concepts: grids, grid refinement
10 
11    Notes: The DMDACreate() based object and the DMCompositeCreate() based object are examples of DMs
12 
13 .seealso:  DMCompositeCreate(), DMDACreate(), DMSetType(), DMType
14 S*/
15 typedef struct _p_DM* DM;
16 
17 /*E
18   DMBoundaryType - Describes the choice for fill of ghost cells on physical domain boundaries.
19 
20   Level: beginner
21 
22   A boundary may be of type DM_BOUNDARY_NONE (no ghost nodes), DM_BOUNDARY_GHOSTED (ghost vertices/cells
23   exist but aren't filled, you can put values into them and then apply a stencil that uses those ghost locations),
24   DM_BOUNDARY_MIRROR (the ghost value is the same as the value 1 grid point in; that is the 0th grid point in the real mesh acts like a mirror to define the ghost point value;
25   not yet implemented for 3d), DM_BOUNDARY_PERIODIC (ghost vertices/cells filled by the opposite
26   edge of the domain), or DM_BOUNDARY_TWIST (like periodic, only glued backwards like a Mobius strip).
27 
28   Note: This is information for the boundary of the __PHYSICAL__ domain. It has nothing to do with boundaries between
29   processes, that width is always determined by the stencil width, see DMDASetStencilWidth().
30 
31   Note: If the physical grid points have values  0 1 2 3 with DM_BOUNDARY_MIRROR then the local vector with ghost points has the values 1 0 1 2 3 2
32 
33   Developer notes: Should DM_BOUNDARY_MIRROR have the same meaning with DMDA_Q0, that is a staggered grid? In that case should the ghost point have the same value
34   as the 0th grid point where the physical boundary serves as the mirror?
35 
36   References: http://scicomp.stackexchange.com/questions/5355/writing-the-poisson-equation-finite-difference-matrix-with-neumann-boundary-cond
37 
38 .seealso: DMDASetBoundaryType(), DMDACreate1d(), DMDACreate2d(), DMDACreate3d(), DMDACreate()
39 E*/
40 typedef enum {DM_BOUNDARY_NONE, DM_BOUNDARY_GHOSTED, DM_BOUNDARY_MIRROR, DM_BOUNDARY_PERIODIC, DM_BOUNDARY_TWIST} DMBoundaryType;
41 
42 /*E
43   DMPointLocationType - Describes the method to handle point location failure
44 
45   Level: beginner
46 
47   If a search using DM_POINTLOCATION_NONE fails, the failure is signaled with a negative cell number. On the
48   other hand, if DM_POINTLOCATION_NEAREST is used, on failure, the (approximate) nearest point in the mesh is
49   used, replacing the given point in the input vector. DM_POINTLOCATION_REMOVE returns values only for points
50   which were located.
51 
52 .seealso: DMLocatePoints()
53 E*/
54 typedef enum {DM_POINTLOCATION_NONE, DM_POINTLOCATION_NEAREST, DM_POINTLOCATION_REMOVE} DMPointLocationType;
55 
56 /*S
57   PetscPartitioner - PETSc object that manages a graph partitioner
58 
59   Level: intermediate
60 
61   Concepts: partition, mesh
62 
63 .seealso: PetscPartitionerCreate(), PetscPartitionerSetType(), PetscPartitionerType
64 S*/
65 typedef struct _p_PetscPartitioner *PetscPartitioner;
66 
67 #endif
68