# 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 on dm


## 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
 `DMCreateMassMatrix()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/interface/dm.c.html#DMCreateMassMatrixLumped">src/dm/interface/dm.c</A>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/plex/plex.c.html#DMCreateMassMatrixLumped_Plex">DMCreateMassMatrixLumped_Plex in src/dm/impls/plex/plex.c</A><BR>


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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](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
