:orphan:
# DMCreateMassMatrixLumped
Gets the lumped mass matrix for a given `DM`
## Synopsis
```
#include "petscdm.h"
#include "petscdmlabel.h"
#include "petscds.h"
PetscErrorCode DMCreateMassMatrixLumped(DM dm, Vec *lm)
```
Collective
## Input Parameter
- ***dm -*** the `DM` object
## Output Parameter
- ***lm -*** the lumped mass matrix, which is a diagonal matrix, represented as a vector
## Note
See `DMCreateMassMatrix()` for how to create the non-lumped version of the mass matrix.
## See Also
[](ch_dmbase), `DM`, `DMCreateMassMatrix()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`
## Level
developer
## Location
src/dm/interface/dm.c
## Implementations
DMCreateMassMatrixLumped_Plex in src/dm/impls/plex/plex.c
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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/dm/interface/dm.c)
[Index of all DM routines](index.md)
[Table of Contents for all manual pages](/manualpages/index.md)
[Index of all manual pages](/manualpages/singleindex.md)