Date: 2026-05-01T06:12:04+00:00

Actual source code: sprng.c

      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 (rander48|rand|rand48|sprng|random123|curand) - set the random number generator from the options database, see `PetscRandomType`.

     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: }