# DMSwarmRegisterUserDatatypeField
Register a user defined data type to a DMSwarm 
## Synopsis
```
#include "petscdmswarm.h"   
PetscErrorCode DMSwarmRegisterUserDatatypeField(DM dm, const char fieldname[], size_t size, PetscInt blocksize)
```
Collective on dm


## Input parameters

- ***dm -*** a DMSwarm
- ***fieldname -*** the textual name to identify this field
- ***size -*** the size in bytes of the user data type
- ***blocksize -*** the number of each data type





## Notes
The textual name for each registered field must be unique.


## See Also
 `DMSwarmRegisterPetscDatatypeField()`, `DMSwarmRegisterUserStructField()`, `DMSwarmRegisterUserDatatypeField()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/swarm/swarm.c.html#DMSwarmRegisterUserDatatypeField">src/dm/impls/swarm/swarm.c</A>


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


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