:orphan:
# PetscViewerGLVisSetFields
Sets the required information to visualize different fields from a vector. 
## Synopsis
```
#include "petscviewer.h" 
#include "petscsys.h"    
PetscErrorCode PetscViewerGLVisSetFields(PetscViewer viewer, PetscInt nf, const char *fec_type[], PetscInt dim[], PetscErrorCode (*g2l)(PetscObject, PetscInt, PetscObject[], void *), PetscObject Vfield[], void *ctx, PetscErrorCode (*destroyctx)(void *))
```
Logically Collective


## Input Parameters

- ***viewer     -*** the `PetscViewer` of type `PETSCVIEWERGLVIS`
- ***nf         -*** number of fields to be visualized
- ***fec_type   -*** the type of finite element to be used to visualize the data (see FiniteElementCollection::Name() in MFEM)
- ***dim        -*** array of space dimension for field vectors (used to initialize the scene)
- ***g2lfields  -*** User routine to compute the local field vectors to be visualized; PetscObject is used in place of Vec on the prototype
- ***Vfield     -*** array of work vectors, one for each field
- ***ctx        -*** User context to store the relevant data to apply g2lfields
- ***destroyctx -*** Destroy function for userctx





## Notes
`g2lfields` is called on the vector V to be visualized in order to extract the relevant dofs to be put in `Vfield`, as
```none
  g2lfields((PetscObject)V,nfields,(PetscObject*)Vfield[],ctx).
```


For vector spaces, the block size of `Vfield`[i] represents the vector dimension.
The names of the `Vfield` vectors will be displayed in the window title.


## See Also
 [](sec_viewers), `PETSCVIEWERGLVIS`, `PetscViewerGLVisOpen()`, `PetscViewerCreate()`, `PetscViewerSetType()`, `PetscObjectSetName()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/classes/viewer/impls/glvis/glvis.c.html#PetscViewerGLVisSetFields">src/sys/classes/viewer/impls/glvis/glvis.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex43.c.html">src/ksp/ksp/tutorials/ex43.c</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/classes/viewer/impls/glvis/glvis.c.html#PetscViewerGLVisSetFields_GLVis(PetscViewer viewer, PetscInt nfields, const char *fec_type[], PetscInt dim[], PetscErrorCode (*g2l)(PetscObject, PetscInt, PetscObject[], void *), PetscObject Vfield[], void *ctx, PetscErrorCode (*destroyctx)">PetscViewerGLVisSetFields_GLVis(PetscViewer viewer, PetscInt nfields, const char *fec_type[], PetscInt dim[], PetscErrorCode (*g2l)(PetscObject, PetscInt, PetscObject[], void *), PetscObject Vfield[], void *ctx, PetscErrorCode (*destroyctx) in src/sys/classes/viewer/impls/glvis/glvis.c</A><BR>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/classes/viewer/impls/glvis/glvis.c)


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