# PETSCRANDOM123
access to Random123 counter based pseudorandom number generators (currently threefry4x64) 
## Options Database Keys

- ***-random_type <rand,rand48,sprng,random123> -*** select the random number generator at runtim



## Note
PETSc must be ./configure with the option --download-random123 to use this random number generator.




## See Also
 `RandomCreate()`, `RandomSetType()`, `PETSCRAND`, `PETSCRAND48`, `PETSCSPRNG`, `PetscRandomSetFromOptions()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/classes/random/impls/random123/random123.c.html#PETSCRANDOM123">src/sys/classes/random/impls/random123/random123.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/classes/random/impls/random123/random123.c)


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