petsc-3.14.5 2021-03-03
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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 on dm

### 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

DMCreateGlobalVector(), VecDuplicate(), VecDuplicateVecs(),
DMDACreate1d(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(), DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMCreateLocalVector(), DMRestoreLocalVector() VecStrideMax(), VecStrideMin(), VecStrideNorm()

### Level

beginner

### Location

src/dm/interface/dmget.c

### Examples

src/dm/impls/plex/tutorials/ex1.c.html
src/dm/impls/plex/tutorials/ex7.c.html
src/dm/impls/plex/tutorials/ex1f90.F90.html
src/dm/impls/stag/tutorials/ex1.c.html
src/dm/impls/stag/tutorials/ex2.c.html
src/dm/impls/stag/tutorials/ex3.c.html
src/dm/tutorials/ex12.c.html
src/dm/tutorials/ex51.c.html
src/dm/tutorials/ex11f90.F90.html
src/ksp/ksp/tutorials/ex73.c.html
src/snes/tutorials/ex12.c.html
Index of all DM routines
Table of Contents for all manual pages
Index of all manual pages