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

  4: PetscErrorCode  PetscRandomSeed_Rand(PetscRandom r)
  5: {
  6:   srand(r->seed);
  7:   return 0;
  8: }

 10: #define RAND_WRAP ((PetscReal)((rand()/(double)((unsigned int)RAND_MAX+1))))
 11: PetscErrorCode  PetscRandomGetValue_Rand(PetscRandom r,PetscScalar *val)
 12: {
 13: #if defined(PETSC_USE_COMPLEX)
 14:   if (r->iset) *val = PetscRealPart(r->width)*RAND_WRAP + PetscRealPart(r->low) + (PetscImaginaryPart(r->width)*RAND_WRAP + PetscImaginaryPart(r->low)) * PETSC_i;
 15:   else *val = RAND_WRAP + RAND_WRAP*PETSC_i;
 16: #else
 17:   if (r->iset) *val = r->width * RAND_WRAP + r->low;
 18:   else         *val = RAND_WRAP;
 19: #endif
 20:   return 0;
 21: }

 23: PetscErrorCode  PetscRandomGetValueReal_Rand(PetscRandom r,PetscReal *val)
 24: {
 25: #if defined(PETSC_USE_COMPLEX)
 26:     if (r->iset) *val = PetscRealPart(r->width)*RAND_WRAP + PetscRealPart(r->low);
 27:     else         *val = RAND_WRAP;
 28: #else
 29:   if (r->iset) *val = r->width * RAND_WRAP + r->low;
 30:   else         *val = RAND_WRAP;
 31: #endif
 32:   return 0;
 33: }

 35: static struct _PetscRandomOps PetscRandomOps_Values = {
 36:   PetscDesignatedInitializer(seed,PetscRandomSeed_Rand),
 37:   PetscDesignatedInitializer(getvalue,PetscRandomGetValue_Rand),
 38:   PetscDesignatedInitializer(getvaluereal,PetscRandomGetValueReal_Rand),
 39: };

 41: /*MC
 42:    PETSCRAND - access to the basic Unix random number generator

 44:    Options Database Keys:
 45: . -random_type <rand,rand48,sprng>

 47:   Level: beginner

 49: .seealso: PetscRandomCreate(), PetscRandomSetType(), PETSCRAND48, PETSCSPRNG
 50: M*/

 52: PETSC_EXTERN PetscErrorCode PetscRandomCreate_Rand(PetscRandom r)
 53: {
 54:   PetscMemcpy(r->ops,&PetscRandomOps_Values,sizeof(PetscRandomOps_Values));
 55:   PetscObjectChangeTypeName((PetscObject)r,PETSCRAND);
 56:   return 0;
 57: }