DMStagVecGetValuesStencil

get vector values using grid indexing

Synopsis

#include "petscdmstag.h"   
PetscErrorCode DMStagVecGetValuesStencil(DM dm, Vec vec, PetscInt n, const DMStagStencil *pos, PetscScalar *val)

Not Collective

Input Parameters

• dm - the DMSTAG object

• vec - the vector object

• n - the number of values to obtain

• pos - locations to obtain values from (as an array of DMStagStencil values)

Output Parameter

• val - value at the point

Notes

Accepts stencils which refer to global element numbers, but only allows access to entries in the local representation (including ghosts).

This approach is not as efficient as getting values directly with DMStagVecGetArray(), which is recommended for matrix-free operators.

See Also

DMSTAG: Staggered, Structured Grid, DMSTAG, DMStagStencil, DMStagStencilLocation, DMStagVecSetValuesStencil(), DMStagMatSetValuesStencil(), DMStagVecGetArray()

Level

advanced

Location

src/dm/impls/stag/stagstencil.c

Examples

src/dm/impls/stag/tutorials/ex1.c
src/dm/impls/stag/tutorials/ex4.c
src/dm/impls/stag/tutorials/ex6.c

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Index of all DMStag routines
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Index of all manual pages