petsc-3.14.5 2021-03-03
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# VecGetArray3dWrite

Returns a pointer to a 3d contiguous array that will contain this processor's portion of the vector data. You MUST call VecRestoreArray3dWrite() when you no longer need access to the array.

### Synopsis

    #include "petscvec.h"
    PetscErrorCode  VecGetArray3dWrite(Vec x,PetscInt m,PetscInt n,PetscInt p,PetscInt mstart,PetscInt nstart,PetscInt pstart,PetscScalar ***a[])

Logically Collective

### Input Parameter

| x | - the vector
| m | - first dimension of three dimensional array
| n | - second dimension of three dimensional array
| p | - third dimension of three dimensional array
| mstart | - first index you will use in first coordinate direction (often 0)
| nstart | - first index in the second coordinate direction (often 0)
| pstart | - first index in the third coordinate direction (often 0)

### Output Parameter

| a | - location to put pointer to the array

### Notes

For a vector obtained from DMCreateLocalVector() mstart, nstart, and pstart are likely obtained from the corner indices obtained from DMDAGetGhostCorners() while for DMCreateGlobalVector() they are the corner indices from DMDAGetCorners(). In both cases the arguments from DMDAGet[Ghost]Corners() are reversed in the call to VecGetArray3d().

For standard PETSc vectors this is an inexpensive call; it does not copy the vector values.

Concepts: vector^accessing local values as 3d array

### See Also

VecGetArray(), VecRestoreArray(), VecGetArrays(), VecGetArrayF90(), VecPlaceArray(),
VecRestoreArray2d(), DMDAVecGetarray(), DMDAVecRestoreArray(), VecGetArray3d(), VecRestoreArray3d(), VecGetArray1d(), VecRestoreArray1d(), VecGetArray4d(), VecRestoreArray4d()

### Level

developer

### Location

src/vec/vec/interface/rvector.c
Index of all Vec routines
Table of Contents for all manual pages
Index of all manual pages