1: #if !defined(_PETSCDMTYPES_H)
  2: #define _PETSCDMTYPES_H

  4: /*S
  5:      DM - Abstract PETSc object that manages an abstract grid object and its interactions with the algebraic solvers

  7:    Level: intermediate

  9:   Concepts: grids, grid refinement

 11:    Notes: The DMDACreate() based object and the DMCompositeCreate() based object are examples of DMs

 13: .seealso:  DMCompositeCreate(), DMDACreate(), DMSetType(), DMType
 14: S*/
 15: typedef struct _p_DM* DM;

 17: /*E
 18:   DMBoundaryType - Describes the choice for fill of ghost cells on physical domain boundaries.

 20:   Level: beginner

 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).

 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().

 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

 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?

 36:   References: http://scicomp.stackexchange.com/questions/5355/writing-the-poisson-equation-finite-difference-matrix-with-neumann-boundary-cond

 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;

 42: /*E
 43:   DMPointLocationType - Describes the method to handle point location failure

 45:   Level: beginner

 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.

 52: .seealso: DMLocatePoints()
 53: E*/
 54: typedef enum {DM_POINTLOCATION_NONE, DM_POINTLOCATION_NEAREST, DM_POINTLOCATION_REMOVE} DMPointLocationType;

 56: /*S
 57:   PetscPartitioner - PETSc object that manages a graph partitioner

 59:   Level: intermediate

 61:   Concepts: partition, mesh

 63: .seealso: PetscPartitionerCreate(), PetscPartitionerSetType(), PetscPartitionerType
 64: S*/
 65: typedef struct _p_PetscPartitioner *PetscPartitioner;

 67: #endif