DMStagVecGetArray#

get access to local array

Synopsis#

#include "petscdmstag.h"   
#include "petscdmproduct.h"   
PetscErrorCode DMStagVecGetArray(DM dm, Vec vec, void *array)

Logically Collective

Input Parameters#

dm - the DMSTAG object
vec - the Vec object

Output Parameter#

array - the array

Note#

This function returns a (dim+1)-dimensional array for a dim-dimensional DMSTAG.

The first 1-3 dimensions indicate an element in the global numbering, using the standard C ordering.

The final dimension in this array corresponds to a degree of freedom with respect to this element, for example corresponding to the element or one of its neighboring faces, edges, or vertices.

For example, for a 3D DMSTAG, indexing is array[k][j][i][idx], where k is the index in the z-direction, j is the index in the y-direction, and i is the index in the x-direction.

idx is obtained with DMStagGetLocationSlot(), since the correct offset into the \((d+1)\)-dimensional C array for a \(d\)-dimensional DMSTAG depends on the grid size and the number of DOF stored at each location.

DMStagVecRestoreArray() must be called, once finished with the array