petsc-dev 2014-07-12
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DMDAVecGetArray

Returns a multiple dimension array that shares data with the underlying vector and is indexed using the global dimensions.

Synopsis

#include "petscdmda.h"   
PetscErrorCode  DMDAVecGetArray(DM da,Vec vec,void *array)
Collective on Vec

Input Parameter

da - the distributed array
vec - the vector, either a vector the same size as one obtained with DMCreateGlobalVector() or DMCreateLocalVector()

Output Parameter

array -the array

Notes

Call DMDAVecRestoreArray() once you have finished accessing the vector entries.

In C, the indexing is "backwards" from what expects: array[k][j][i] NOT array[i][j][k]!

If vec is a local vector (obtained with DMCreateLocalVector() etc) then they ghost point locations are accessable. If it is a global vector then the ghost points are not accessable. Of course with the local vector you will have had to do the

appropriate DMLocalToGlobalBegin() and DMLocalToGlobalEnd() to have correct values in the ghost locations.

Fortran Notes: From Fortran use DMDAVecGetArrayF90() and pass for the array type PetscScalar,pointer :: array(:,...,:) of the appropriate dimension. For a DMDA created with a dof of 1 use the dimension of the DMDA, for a DMDA created with a dof greater than 1 use one more than the dimension of the DMDA. The order of the indices is array(xs:xs+xm-1,ys:ys+ym-1,zs:zs+zm-1) (when dof is 1) otherwise array(0:dof-1,xs:xs+xm-1,ys:ys+ym-1,zs:zs+zm-1) where the values are obtained from DMDAGetCorners() for a global array or DMDAGetGhostCorners() for a local array. Include finclude/petscdmda.h90 to access this routine.

Due to bugs in the compiler DMDAVecGetArrayF90() does not work with gfortran versions before 4.5

Keywords

distributed array, get, corners, nodes, local indices, coordinates

See Also

DMDAGetGhostCorners(), DMDAGetCorners(), VecGetArray(), VecRestoreArray(), DMDAVecRestoreArray(), DMDAVecRestoreArrayDOF()
DMDAVecGetArrayDOF()

Level:intermediate
Location:
src/dm/impls/da/dagetarray.c
Index of all DM routines
Table of Contents for all manual pages
Index of all manual pages

Examples

src/dm/examples/tutorials/ex3.c.html
src/dm/examples/tutorials/ex10.c.html
src/ksp/ksp/examples/tutorials/ex29.c.html
src/ksp/ksp/examples/tutorials/ex32.c.html
src/ksp/ksp/examples/tutorials/ex34.c.html
src/ksp/ksp/examples/tutorials/ex42.c.html
src/ksp/ksp/examples/tutorials/ex43.c.html
src/ksp/ksp/examples/tutorials/ex45.c.html
src/ksp/ksp/examples/tutorials/ex49.c.html
src/ksp/ksp/examples/tutorials/ex50.c.html
src/snes/examples/tutorials/ex3.c.html