xref: /petsc/src/sys/classes/random/impls/rand/rand.c (revision 8cc058d9cd56c1ccb3be12a47760ddfc446aaffc)
15c6c1daeSBarry Smith 
25c6c1daeSBarry Smith #include <../src/sys/classes/random/randomimpl.h>
35c6c1daeSBarry Smith 
45c6c1daeSBarry Smith #undef __FUNCT__
55c6c1daeSBarry Smith #define __FUNCT__ "PetscRandomSeed_Rand"
65c6c1daeSBarry Smith PetscErrorCode  PetscRandomSeed_Rand(PetscRandom r)
75c6c1daeSBarry Smith {
85c6c1daeSBarry Smith   PetscFunctionBegin;
95c6c1daeSBarry Smith   srand(r->seed);
105c6c1daeSBarry Smith   PetscFunctionReturn(0);
115c6c1daeSBarry Smith }
125c6c1daeSBarry Smith 
135c6c1daeSBarry Smith #define RAND_WRAP ((PetscReal)((rand()/(double)((unsigned int)RAND_MAX+1))))
145c6c1daeSBarry Smith #undef __FUNCT__
155c6c1daeSBarry Smith #define __FUNCT__ "PetscRandomGetValue_Rand"
165c6c1daeSBarry Smith PetscErrorCode  PetscRandomGetValue_Rand(PetscRandom r,PetscScalar *val)
175c6c1daeSBarry Smith {
185c6c1daeSBarry Smith   PetscFunctionBegin;
195c6c1daeSBarry Smith #if defined(PETSC_USE_COMPLEX)
20b0043f70SBarry Smith   if (r->iset) *val = PetscRealPart(r->width)*RAND_WRAP + PetscRealPart(r->low) + (PetscImaginaryPart(r->width)*RAND_WRAP + PetscImaginaryPart(r->low)) * PETSC_i;
215c6c1daeSBarry Smith   else *val = RAND_WRAP + RAND_WRAP*PETSC_i;
225c6c1daeSBarry Smith #else
235c6c1daeSBarry Smith   if (r->iset) *val = r->width * RAND_WRAP + r->low;
245c6c1daeSBarry Smith   else         *val = RAND_WRAP;
255c6c1daeSBarry Smith #endif
265c6c1daeSBarry Smith   PetscFunctionReturn(0);
275c6c1daeSBarry Smith }
285c6c1daeSBarry Smith 
295c6c1daeSBarry Smith #undef __FUNCT__
305c6c1daeSBarry Smith #define __FUNCT__ "PetscRandomGetValueReal_Rand"
315c6c1daeSBarry Smith PetscErrorCode  PetscRandomGetValueReal_Rand(PetscRandom r,PetscReal *val)
325c6c1daeSBarry Smith {
335c6c1daeSBarry Smith   PetscFunctionBegin;
345c6c1daeSBarry Smith #if defined(PETSC_USE_COMPLEX)
355c6c1daeSBarry Smith     if (r->iset) *val = PetscRealPart(r->width)*RAND_WRAP + PetscRealPart(r->low);
365c6c1daeSBarry Smith     else         *val = RAND_WRAP;
375c6c1daeSBarry Smith #else
385c6c1daeSBarry Smith   if (r->iset) *val = r->width * RAND_WRAP + r->low;
395c6c1daeSBarry Smith   else         *val = RAND_WRAP;
405c6c1daeSBarry Smith #endif
415c6c1daeSBarry Smith   PetscFunctionReturn(0);
425c6c1daeSBarry Smith }
435c6c1daeSBarry Smith 
445c6c1daeSBarry Smith static struct _PetscRandomOps PetscRandomOps_Values = {
455c6c1daeSBarry Smith   /* 0 */
465c6c1daeSBarry Smith   PetscRandomSeed_Rand,
475c6c1daeSBarry Smith   PetscRandomGetValue_Rand,
485c6c1daeSBarry Smith   PetscRandomGetValueReal_Rand,
495c6c1daeSBarry Smith   0,
505c6c1daeSBarry Smith   /* 5 */
515c6c1daeSBarry Smith   0
525c6c1daeSBarry Smith };
535c6c1daeSBarry Smith 
545c6c1daeSBarry Smith /*MC
555c6c1daeSBarry Smith    PETSCRAND - access to the basic Unix random number generator
565c6c1daeSBarry Smith 
575c6c1daeSBarry Smith    Options Database Keys:
585c6c1daeSBarry Smith . -random_type <rand,rand48,sprng>
595c6c1daeSBarry Smith 
605c6c1daeSBarry Smith   Level: beginner
615c6c1daeSBarry Smith 
625c6c1daeSBarry Smith .seealso: RandomCreate(), RandomSetType(), PETSCRAND48, PETSCSPRNG
635c6c1daeSBarry Smith M*/
645c6c1daeSBarry Smith 
655c6c1daeSBarry Smith #undef __FUNCT__
665c6c1daeSBarry Smith #define __FUNCT__ "PetscRandomCreate_Rand"
67*8cc058d9SJed Brown PETSC_EXTERN PetscErrorCode PetscRandomCreate_Rand(PetscRandom r)
685c6c1daeSBarry Smith {
695c6c1daeSBarry Smith   PetscErrorCode ierr;
705c6c1daeSBarry Smith 
715c6c1daeSBarry Smith   PetscFunctionBegin;
725c6c1daeSBarry Smith   ierr = PetscMemcpy(r->ops,&PetscRandomOps_Values,sizeof(PetscRandomOps_Values));CHKERRQ(ierr);
735c6c1daeSBarry Smith   ierr = PetscObjectChangeTypeName((PetscObject)r,PETSCRAND);CHKERRQ(ierr);
745c6c1daeSBarry Smith   PetscFunctionReturn(0);
755c6c1daeSBarry Smith }
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