15c6c1daeSBarry Smith 2d6cc7855SJacob Faibussowitsch #include <petsc/private/randomimpl.h> 35c6c1daeSBarry Smith 4d71ae5a4SJacob Faibussowitsch PetscErrorCode PetscRandomSeed_Rand(PetscRandom r) 5d71ae5a4SJacob Faibussowitsch { 65c6c1daeSBarry Smith PetscFunctionBegin; 75c6c1daeSBarry Smith srand(r->seed); 8*3ba16761SJacob Faibussowitsch PetscFunctionReturn(PETSC_SUCCESS); 95c6c1daeSBarry Smith } 105c6c1daeSBarry Smith 115c6c1daeSBarry Smith #define RAND_WRAP ((PetscReal)((rand() / (double)((unsigned int)RAND_MAX + 1)))) 12d71ae5a4SJacob Faibussowitsch PetscErrorCode PetscRandomGetValue_Rand(PetscRandom r, PetscScalar *val) 13d71ae5a4SJacob Faibussowitsch { 145c6c1daeSBarry Smith PetscFunctionBegin; 155c6c1daeSBarry Smith #if defined(PETSC_USE_COMPLEX) 16b0043f70SBarry Smith if (r->iset) *val = PetscRealPart(r->width) * RAND_WRAP + PetscRealPart(r->low) + (PetscImaginaryPart(r->width) * RAND_WRAP + PetscImaginaryPart(r->low)) * PETSC_i; 175c6c1daeSBarry Smith else *val = RAND_WRAP + RAND_WRAP * PETSC_i; 185c6c1daeSBarry Smith #else 195c6c1daeSBarry Smith if (r->iset) *val = r->width * RAND_WRAP + r->low; 205c6c1daeSBarry Smith else *val = RAND_WRAP; 215c6c1daeSBarry Smith #endif 22*3ba16761SJacob Faibussowitsch PetscFunctionReturn(PETSC_SUCCESS); 235c6c1daeSBarry Smith } 245c6c1daeSBarry Smith 25d71ae5a4SJacob Faibussowitsch PetscErrorCode PetscRandomGetValueReal_Rand(PetscRandom r, PetscReal *val) 26d71ae5a4SJacob Faibussowitsch { 275c6c1daeSBarry Smith PetscFunctionBegin; 285c6c1daeSBarry Smith #if defined(PETSC_USE_COMPLEX) 295c6c1daeSBarry Smith if (r->iset) *val = PetscRealPart(r->width) * RAND_WRAP + PetscRealPart(r->low); 305c6c1daeSBarry Smith else *val = RAND_WRAP; 315c6c1daeSBarry Smith #else 325c6c1daeSBarry Smith if (r->iset) *val = r->width * RAND_WRAP + r->low; 335c6c1daeSBarry Smith else *val = RAND_WRAP; 345c6c1daeSBarry Smith #endif 35*3ba16761SJacob Faibussowitsch PetscFunctionReturn(PETSC_SUCCESS); 365c6c1daeSBarry Smith } 375c6c1daeSBarry Smith 385c6c1daeSBarry Smith static struct _PetscRandomOps PetscRandomOps_Values = { 39267267bdSJacob Faibussowitsch PetscDesignatedInitializer(seed, PetscRandomSeed_Rand), 40267267bdSJacob Faibussowitsch PetscDesignatedInitializer(getvalue, PetscRandomGetValue_Rand), 41267267bdSJacob Faibussowitsch PetscDesignatedInitializer(getvaluereal, PetscRandomGetValueReal_Rand), 425c6c1daeSBarry Smith }; 435c6c1daeSBarry Smith 445c6c1daeSBarry Smith /*MC 455c6c1daeSBarry Smith PETSCRAND - access to the basic Unix random number generator 465c6c1daeSBarry Smith 475c6c1daeSBarry Smith Options Database Keys: 481179163eSBarry Smith . -random_type <rand,rand48,sprng> - set the random number generator from the options database 495c6c1daeSBarry Smith 505c6c1daeSBarry Smith Level: beginner 515c6c1daeSBarry Smith 52811af0c4SBarry Smith Note: 53811af0c4SBarry Smith Not recommended since it can produce different numbers on different systems 54811af0c4SBarry Smith 55811af0c4SBarry Smith .seealso: `PetscRandomCreate()`, `PetscRandomSetType()`, `PETSCRAND48`, `PETSCSPRNG`, `PetscRandomSetFromOptions()`, `PetscRandomType` 565c6c1daeSBarry Smith M*/ 575c6c1daeSBarry Smith 58d71ae5a4SJacob Faibussowitsch PETSC_EXTERN PetscErrorCode PetscRandomCreate_Rand(PetscRandom r) 59d71ae5a4SJacob Faibussowitsch { 605c6c1daeSBarry Smith PetscFunctionBegin; 619566063dSJacob Faibussowitsch PetscCall(PetscMemcpy(r->ops, &PetscRandomOps_Values, sizeof(PetscRandomOps_Values))); 629566063dSJacob Faibussowitsch PetscCall(PetscObjectChangeTypeName((PetscObject)r, PETSCRAND)); 63*3ba16761SJacob Faibussowitsch PetscFunctionReturn(PETSC_SUCCESS); 645c6c1daeSBarry Smith } 65