# PetscRandomSetFromOptions
Configures the random number generator from the options database. 
## Synopsis
```
#include "petscsys.h" 
PetscErrorCode PetscRandomSetFromOptions(PetscRandom rnd)
```
Collective on rnd


## Input Parameter

- ***rnd -*** The random number generator context



## Options Database Keys

- ***-random_seed <integer> -*** provide a seed to the random number generater
- ***-random_no_imaginary_part -*** makes the imaginary part of the random number zero, this is useful when you want the
same code to produce the same result when run with real numbers or complex numbers for regression testing purposes



## Note
Must be called after `PetscRandomCreate()` but before the rnd is used.




## See Also
 `PetscRandom`, `PetscRandomCreate()`, `PetscRandomSetType()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/classes/random/interface/randomc.c.html#PetscRandomSetFromOptions">src/sys/classes/random/interface/randomc.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/classes/random/tutorials/ex1.c.html">src/sys/classes/random/tutorials/ex1.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/classes/random/tutorials/ex2.c.html">src/sys/classes/random/tutorials/ex2.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/vec/utils/tagger/tutorials/ex1.c.html">src/vec/vec/utils/tagger/tutorials/ex1.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/vec/tutorials/ex19.c.html">src/vec/vec/tutorials/ex19.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/vec/tutorials/performance.c.html">src/vec/vec/tutorials/performance.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/field/tutorials/ex1.c.html">src/dm/field/tutorials/ex1.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/tutorials/ex3.c.html">src/ksp/pc/tutorials/ex3.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex11.c.html">src/ksp/ksp/tutorials/ex11.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex11f.F90.html">src/ksp/ksp/tutorials/ex11f.F90.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex18.c.html">src/ksp/ksp/tutorials/ex18.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex21.c.html">src/ksp/ksp/tutorials/ex21.c.html</A><BR>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/classes/random/interface/randomc.c)


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[Index of all manual pages](/docs/manualpages/singleindex.md)  
