DMGetGlobalVector — PETSc 3.24.5 documentation

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# DMGetGlobalVector

Gets a PETSc vector that may be used with the `DM` global routines.

## Synopsis

    #include "petscdm.h"
    PetscErrorCode DMGetGlobalVector(DM dm, Vec *g)

Collective

## Input Parameter

- dm - the `DM`

## Output Parameter

- g - the global vector

## Note

The vector values are NOT initialized and may have garbage in them, so you may need to zero them.

The output parameter, `g`, is a regular PETSc vector that should be returned with `DMRestoreGlobalVector()` DO NOT call `VecDestroy()` on it.

This is intended to be used for vectors you need for a short time, like within a single function call. For vectors that you intend to keep around (for example in a C struct) or pass around large parts of your code you should use `DMCreateGlobalVector()`.

VecStride*() operations can be useful when using `DM` with dof > 1

## See Also

`DM`, `DMCreateGlobalVector()`, `VecDuplicate()`, `VecDuplicateVecs()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMGlobalToLocalBegin()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`, `DMCreateLocalVector()`, `DMRestoreLocalVector()` `VecStrideMax()`, `VecStrideMin()`, `VecStrideNorm()`, `DMClearGlobalVectors()`, `DMGetNamedGlobalVector()`, `DMGetNamedLocalVector()`

## Level

beginner

## Location

src/dm/interface/dmget.c

## Examples

src/dm/impls/plex/tutorials/ex7.c
src/dm/impls/plex/tutorials/ex1f90.F90
src/dm/impls/stag/tutorials/ex2.c
src/dm/tutorials/ex14.c
src/dm/impls/stag/tutorials/ex4.c
src/dm/impls/plex/tutorials/ex1.c
src/dm/impls/stag/tutorials/ex1.c
src/dm/impls/plex/tutorials/ex15.c
src/dm/impls/stag/tutorials/ex3.c
src/dm/impls/plex/tutorials/ex16.c

Index of all DM routines
Table of Contents for all manual pages
Index of all manual pages