# PetscFECompositeGetMapping
Returns the mappings from the reference element to each subelement 
## Synopsis
```
#include "petscfe.h" 
#include "petscdt.h" 
PetscErrorCode PetscFECompositeGetMapping(PetscFE fem, PetscInt *numSubelements, const PetscReal *v0[], const PetscReal *jac[], const PetscReal *invjac[])
```
Not collective


## Input Parameter

- ***fem -*** The `PetscFE` object



## Output Parameters

- ***blockSize -*** The number of elements in a block
- ***numBlocks -*** The number of blocks in a batch
- ***batchSize -*** The number of elements in a batch
- ***numBatches -*** The number of batches in a chunk





## See Also
 `PetscFE`, `PetscFECreate()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/dt/fe/impls/composite/fecomposite.c.html#PetscFECompositeGetMapping">src/dm/dt/fe/impls/composite/fecomposite.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/dm/dt/fe/impls/composite/fecomposite.c)


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