1: #define PETSC_DESIRE_FEATURE_TEST_MACROS /* for drand48 with c89 */
  2: #include <../src/sys/classes/random/randomimpl.h>

  6: PetscErrorCode  PetscRandomSeed_Rand48(PetscRandom r)
  7: {
  9:   srand48(r->seed);
 10:   return(0);
 11: }

 15: PetscErrorCode  PetscRandomGetValue_Rand48(PetscRandom r,PetscScalar *val)
 16: {
 18: #if defined(PETSC_USE_COMPLEX)
 19:   if (r->iset) {
 20:     *val = PetscRealPart(r->width)*(PetscReal)drand48() + PetscRealPart(r->low) + (PetscImaginaryPart(r->width)*(PetscReal)drand48() + PetscImaginaryPart(r->low)) * PETSC_i;
 21:   } else {
 22:     *val = (PetscReal)drand48() + (PetscReal)drand48()*PETSC_i;
 23:   }
 24: #else
 25:   if (r->iset) *val = r->width * drand48() + r->low;
 26:   else         *val = drand48();
 27: #endif
 28:   return(0);
 29: }

 33: PetscErrorCode  PetscRandomGetValueReal_Rand48(PetscRandom r,PetscReal *val)
 34: {
 36: #if defined(PETSC_USE_COMPLEX)
 37:   if (r->iset) *val = PetscRealPart(r->width)*drand48() + PetscRealPart(r->low);
 38:   else         *val = drand48();
 39: #else
 40:   if (r->iset) *val = r->width * drand48() + r->low;
 41:   else         *val = drand48();
 42: #endif
 43:   return(0);
 44: }

 46: static struct _PetscRandomOps PetscRandomOps_Values = {
 47:   /* 0 */
 48:   PetscRandomSeed_Rand48,
 49:   PetscRandomGetValue_Rand48,
 50:   PetscRandomGetValueReal_Rand48,
 51:   0,
 52:   /* 5 */
 53:   0
 54: };

 56: /*MC
 57:    PETSCRAND48 - access to the basic Unix drand48() random number generator

 59:    Options Database Keys:
 60: . -random_type <rand,rand48,sprng>

 62:   Level: beginner

 64: .seealso: RandomCreate(), RandomSetType(), PETSCRAND, PETSCSPRNG
 65: M*/

 69: PETSC_EXTERN PetscErrorCode PetscRandomCreate_Rand48(PetscRandom r)
 70: {

 74:   PetscMemcpy(r->ops,&PetscRandomOps_Values,sizeof(PetscRandomOps_Values));
 75:   PetscObjectChangeTypeName((PetscObject)r,PETSCRAND48);
 76:   return(0);
 77: }