1: #include <petsc/private/randomimpl.h>

  3: #define USE_MPI
  4: #define SIMPLE_SPRNG
  5: EXTERN_C_BEGIN
  6: #include <sprng.h>
  7: EXTERN_C_END

  9: static PetscErrorCode PetscRandomSeed_Sprng(PetscRandom r)
 10: {
 11:   PetscFunctionBegin;
 12:   init_sprng(r->seed, SPRNG_DEFAULT);
 13:   PetscFunctionReturn(PETSC_SUCCESS);
 14: }

 16: static PetscErrorCode PetscRandomGetValue_Sprng(PetscRandom r, PetscScalar *val)
 17: {
 18:   PetscFunctionBegin;
 19: #if defined(PETSC_USE_COMPLEX)
 20:   if (r->iset) {
 21:     *val = PetscRealPart(r->width) * sprng() + PetscRealPart(r->low) + (PetscImaginaryPart(r->width) * sprng() + PetscImaginaryPart(r->low)) * PETSC_i;
 22:   } else {
 23:     *val = sprng() + sprng() * PETSC_i;
 24:   }
 25: #else
 26:   if (r->iset) *val = r->width * sprng() + r->low;
 27:   else *val = sprng();
 28: #endif
 29:   PetscFunctionReturn(PETSC_SUCCESS);
 30: }

 32: static PetscErrorCode PetscRandomGetValueReal_Sprng(PetscRandom r, PetscReal *val)
 33: {
 34:   PetscFunctionBegin;
 35: #if defined(PETSC_USE_COMPLEX)
 36:   if (r->iset) *val = PetscRealPart(r->width) * sprng() + PetscRealPart(r->low);
 37:   else *val = sprng();
 38: #else
 39:   if (r->iset) *val = r->width * sprng() + r->low;
 40:   else *val = sprng();
 41: #endif
 42:   PetscFunctionReturn(PETSC_SUCCESS);
 43: }

 45: static struct _PetscRandomOps PetscRandomOps_Values = {
 46:   PetscDesignatedInitializer(seed, PetscRandomSeed_Sprng),
 47:   PetscDesignatedInitializer(getvalue, PetscRandomGetValue_Sprng),
 48:   PetscDesignatedInitializer(getvaluereal, PetscRandomGetValueReal_Sprng),
 49: };

 51: /*MC
 52:    PETSCSPRNG - access to the publicly available random number generator sprng

 54:    Options Database Key:
 55: . -random_type <rand,rand48,sprng> - select the random number generator at runtime

 57:   Level: beginner

 59:    Note:
 60:    PETSc must be ./configure with the option --download-sprng to use this random number generator.

 62:    Developer Note:
 63:    This is NOT currently using a parallel random number generator. Sprng does have
 64:    an MPI version we should investigate.

 66: .seealso: `RandomCreate()`, `RandomSetType()`, `PETSCRAND`, `PETSCRAND48`, `PetscRandomSetFromOptions()`
 67: M*/

 69: PETSC_EXTERN PetscErrorCode PetscRandomCreate_Sprng(PetscRandom r)
 70: {
 71:   PetscFunctionBegin;
 72:   r->ops[0] = PetscRandomOps_Values;
 73:   PetscCall(PetscObjectChangeTypeName((PetscObject)r, PETSCSPRNG));
 74:   PetscFunctionReturn(PETSC_SUCCESS);
 75: }