DMBoundaryType#

Describes the choice for the filling of ghost cells on physical domain boundaries.

Synopsis#

Values#

  • DM_BOUNDARY_NONE - no ghost nodes

  • DM_BOUNDARY_GHOSTED - ghost vertices/cells exist but aren’t filled; you can put values into them and then apply a stencil that uses those ghost locations

  • 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; not yet implemented for 3d

  • DM_BOUNDARY_PERIODIC - ghost vertices/cells filled by the opposite edge of the domain

  • DM_BOUNDARY_TWIST - like periodic, only glued backwards like a Mobius strip

Notes#

This is information for the boundary of the PHYSICAL domain. It has nothing to do with boundaries between processes. That width is always determined by the stencil width; see DMDASetStencilWidth().

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.

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

Developer Note#

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 as the 0th grid point where the physical boundary serves as the mirror?

See Also#

DM Basics, DM, DMDA, DMDASetBoundaryType(), DMDACreate1d(), DMDACreate2d(), DMDACreate3d(), DMDACreate()

Level#

beginner

Location#

include/petscdmtypes.h

Examples#

src/tao/unconstrained/tutorials/spectraladjointassimilation.c
src/snes/tutorials/ex48.c
src/ts/tutorials/extchemfield.c
src/dm/tutorials/ex2.c
src/snes/tutorials/ex78.c
src/tao/unconstrained/tutorials/burgers_spectral.c
src/dm/impls/stag/tutorials/ex1.c
src/dm/tutorials/ex19.c

Examples#

src/dm/impls/stag/tutorials/ex3.c
src/dm/tutorials/ex19.c
src/dm/tutorials/ex6.c

Examples#

src/ksp/ksp/tutorials/ex66.c

Examples#

src/tao/bound/tutorials/jbearing2.c
src/tao/complementarity/tutorials/blackscholes.c
src/tao/unconstrained/tutorials/minsurf2.c
src/dm/impls/stag/tutorials/ex3.c
src/dm/impls/stag/tutorials/ex1.c
src/tao/unconstrained/tutorials/eptorsion2.c
src/dm/impls/stag/tutorials/ex4.c
src/dm/impls/stag/tutorials/ex6.c
src/dm/impls/stag/tutorials/ex8.c
src/tao/bound/tutorials/plate2.c

Examples#

src/dm/tutorials/ex3.c
src/dm/tutorials/ex1.c
src/dm/tutorials/ex13f90.F90
src/dm/tutorials/ex13f90aux.F90
src/dm/dt/dualspace/impls/lagrange/tutorials/ex2.c
src/snes/tutorials/ex30.c
src/dm/impls/stag/tutorials/ex1.c
src/dm/impls/plex/tutorials/ex13.c
src/dm/tutorials/ex12.c
src/dm/tutorials/ex5.c


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Index of all manual pages