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DMDA

The DMDA (Distributed Array) module provides functionality for creating and managing structured grids in 1D, 2D, or 3D.

Overview

DMDA is ideal for problems on regular structured grids where:

  • The grid is logically rectangular
  • Each grid point has the same number of degrees of freedom
  • Stencil operations follow a regular pattern (star or box stencils)

Creating a DMDA

# 2D grid example
da = DMDA(
    petsclib,
    MPI.COMM_WORLD,
    (DM_BOUNDARY_NONE, DM_BOUNDARY_NONE),  # boundary types
    (nx, ny),                               # global dimensions
    1,                                      # degrees of freedom per node
    1,                                      # stencil width
    DMDA_STENCIL_STAR                      # stencil type
)

Functions

PETSc.DMDA — Method
DMDA(
    petsclib::PetscLib
    comm::MPI.Comm,
    boundary_type::NTuple{D, DMBoundaryType},
    global_dim::NTuple{D, Integer},
    dof_per_node::Integer,
    stencil_width::Integer,
    stencil_type;
    points_per_proc::Tuple,
    processors::Tuple,
    setfromoptions = true,
    dmsetup = true,
    prefix = "",
    options...
)

Creates a D-dimensional distributed array with the options specified using keyword arguments.

If keyword argument points_per_proc[k] isa Vector{petsclib.PetscInt} then this specifies the points per processor in dimension k.

If keyword argument processors[k] isa Integer then this specifies the number of processors used in dimension k; ignored when D == 1.

If keyword argument setfromoptions == true then setfromoptions! called.

If keyword argument dmsetup == true then setup! is called.

When D == 1 the stencil_type argument is not required and ignored if specified.

External Links

source
PETSc.localinteriorlinearindex — Method
ind = localinteriorlinearindex(dmda::AbstractPetscDM)

Returns the linear indices associated with the degrees of freedom own by this MPI rank embedded in the ghost index space for the dmda

source
PETSc.reshapelocalarray — Method
reshapelocalarray(Arr, da::AbstractPetscDM{PetscLib}, ndof = ndofs(da))

Returns an array with the same data as Arr but reshaped as an array that can be addressed with global indexing.

source