# DMPlexLandauCreateMassMatrix
Create mass matrix for Landau in Plex space (not field major order of Jacobian) - puts mass matrix into ctx->M 
## Synopsis
```
#include "petscdmplex.h" 
#include "petsclandau.h"   
PetscErrorCode DMPlexLandauCreateMassMatrix(DM pack, Mat *Amat)
```
Collective


## Input/Output Parameters

- ***pack     -*** the DM object. Puts matrix in Landau context M field



## Output Parameters

- ***Amat -*** The mass matrix (optional), mass matrix is added to the DM context




.keywords: mesh
.seealso: `DMPlexLandauCreateVelocitySpace()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/utils/dmplexlandauplexland.c.html#DMPlexLandauCreateMassMatrix">src/ts/utils/dmplexlandauplexland.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ts/utils/dmplexlandauplexland.c)


[Index of all LANDAU routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
