Actual source code: rand48.c

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

      4: PetscErrorCode  PetscRandomSeed_Rand48(PetscRandom r)
      5: {
      7:   srand48(r->seed);
      8:   return(0);
      9: }

     11: PetscErrorCode  PetscRandomGetValue_Rand48(PetscRandom r,PetscScalar *val)
     12: {
     14: #if defined(PETSC_USE_COMPLEX)
     15:   if (r->iset) {
     16:     *val = PetscRealPart(r->width)*(PetscReal)drand48() + PetscRealPart(r->low) + (PetscImaginaryPart(r->width)*(PetscReal)drand48() + PetscImaginaryPart(r->low)) * PETSC_i;
     17:   } else {
     18:     *val = (PetscReal)drand48() + (PetscReal)drand48()*PETSC_i;
     19:   }
     20: #else
     21:   if (r->iset) *val = r->width * drand48() + r->low;
     22:   else         *val = drand48();
     23: #endif
     24:   return(0);
     25: }

     27: PetscErrorCode  PetscRandomGetValueReal_Rand48(PetscRandom r,PetscReal *val)
     28: {
     30: #if defined(PETSC_USE_COMPLEX)
     31:   if (r->iset) *val = PetscRealPart(r->width)*drand48() + PetscRealPart(r->low);
     32:   else         *val = drand48();
     33: #else
     34:   if (r->iset) *val = r->width * drand48() + r->low;
     35:   else         *val = drand48();
     36: #endif
     37:   return(0);
     38: }

     40: static struct _PetscRandomOps PetscRandomOps_Values = {
     41:   PetscRandomSeed_Rand48,
     42:   PetscRandomGetValue_Rand48,
     43:   PetscRandomGetValueReal_Rand48,
     44:   NULL,
     45:   NULL,
     46:   NULL,
     47:   NULL
     48: };

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

     53:    Options Database Keys:
     54: . -random_type <rand,rand48,sprng>

     56:   Level: beginner

     58: .seealso: PetscRandomCreate(), PetscRandomSetType(), PETSCRAND, PETSCSPRNG
     59: M*/

     61: PETSC_EXTERN PetscErrorCode PetscRandomCreate_Rand48(PetscRandom r)
     62: {

     66:   PetscMemcpy(r->ops,&PetscRandomOps_Values,sizeof(PetscRandomOps_Values));
     67:   PetscObjectChangeTypeName((PetscObject)r,PETSCRAND48);
     68:   return(0);
     69: }