# PetscDrawIsNull
Returns `PETSC_TRUE` if draw is a null draw object. 
## Synopsis
```
#include "petscdraw.h" 
PetscErrorCode PetscDrawIsNull(PetscDraw draw, PetscBool *yes)
```
Not collective


## Input Parameter

- ***draw -*** the draw context



## Output Parameter

- ***yes -*** `PETSC_TRUE` if it is a null draw object; otherwise `PETSC_FALSE`





## See Also
 `PetscDraw`, `PETSC_DRAW_NULL`, `PetscDrawOpenX()`, `PetscDrawIsNull()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/classes/draw/impls/null/drawnull.c.html#PetscDrawIsNull">src/sys/classes/draw/impls/null/drawnull.c</A>


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


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