1d6cc7855SJacob Faibussowitsch #include <petsc/private/randomimpl.h> 25c6c1daeSBarry Smith 366976f2fSJacob Faibussowitsch static PetscErrorCode PetscRandomSeed_Rand(PetscRandom r) 4d71ae5a4SJacob Faibussowitsch { 55c6c1daeSBarry Smith PetscFunctionBegin; 65c6c1daeSBarry Smith srand(r->seed); 73ba16761SJacob Faibussowitsch PetscFunctionReturn(PETSC_SUCCESS); 85c6c1daeSBarry Smith } 95c6c1daeSBarry Smith 10*f4f49eeaSPierre Jolivet #define RAND_WRAP ((PetscReal)(rand() / (double)((unsigned int)RAND_MAX + 1))) 1166976f2fSJacob Faibussowitsch static PetscErrorCode PetscRandomGetValue_Rand(PetscRandom r, PetscScalar *val) 12d71ae5a4SJacob Faibussowitsch { 135c6c1daeSBarry Smith PetscFunctionBegin; 145c6c1daeSBarry Smith #if defined(PETSC_USE_COMPLEX) 15b0043f70SBarry Smith if (r->iset) *val = PetscRealPart(r->width) * RAND_WRAP + PetscRealPart(r->low) + (PetscImaginaryPart(r->width) * RAND_WRAP + PetscImaginaryPart(r->low)) * PETSC_i; 165c6c1daeSBarry Smith else *val = RAND_WRAP + RAND_WRAP * PETSC_i; 175c6c1daeSBarry Smith #else 185c6c1daeSBarry Smith if (r->iset) *val = r->width * RAND_WRAP + r->low; 195c6c1daeSBarry Smith else *val = RAND_WRAP; 205c6c1daeSBarry Smith #endif 213ba16761SJacob Faibussowitsch PetscFunctionReturn(PETSC_SUCCESS); 225c6c1daeSBarry Smith } 235c6c1daeSBarry Smith 2466976f2fSJacob Faibussowitsch static PetscErrorCode PetscRandomGetValueReal_Rand(PetscRandom r, PetscReal *val) 25d71ae5a4SJacob Faibussowitsch { 265c6c1daeSBarry Smith PetscFunctionBegin; 275c6c1daeSBarry Smith #if defined(PETSC_USE_COMPLEX) 285c6c1daeSBarry Smith if (r->iset) *val = PetscRealPart(r->width) * RAND_WRAP + PetscRealPart(r->low); 295c6c1daeSBarry Smith else *val = RAND_WRAP; 305c6c1daeSBarry Smith #else 315c6c1daeSBarry Smith if (r->iset) *val = r->width * RAND_WRAP + r->low; 325c6c1daeSBarry Smith else *val = RAND_WRAP; 335c6c1daeSBarry Smith #endif 343ba16761SJacob Faibussowitsch PetscFunctionReturn(PETSC_SUCCESS); 355c6c1daeSBarry Smith } 365c6c1daeSBarry Smith 375c6c1daeSBarry Smith static struct _PetscRandomOps PetscRandomOps_Values = { 38267267bdSJacob Faibussowitsch PetscDesignatedInitializer(seed, PetscRandomSeed_Rand), 39267267bdSJacob Faibussowitsch PetscDesignatedInitializer(getvalue, PetscRandomGetValue_Rand), 40267267bdSJacob Faibussowitsch PetscDesignatedInitializer(getvaluereal, PetscRandomGetValueReal_Rand), 415c6c1daeSBarry Smith }; 425c6c1daeSBarry Smith 435c6c1daeSBarry Smith /*MC 445c6c1daeSBarry Smith PETSCRAND - access to the basic Unix random number generator 455c6c1daeSBarry Smith 46c31d2375SBarry Smith Options Database Key: 471179163eSBarry Smith . -random_type <rand,rand48,sprng> - set the random number generator from the options database 485c6c1daeSBarry Smith 495c6c1daeSBarry Smith Level: beginner 505c6c1daeSBarry Smith 51811af0c4SBarry Smith Note: 52811af0c4SBarry Smith Not recommended since it can produce different numbers on different systems 53811af0c4SBarry Smith 54811af0c4SBarry Smith .seealso: `PetscRandomCreate()`, `PetscRandomSetType()`, `PETSCRAND48`, `PETSCSPRNG`, `PetscRandomSetFromOptions()`, `PetscRandomType` 555c6c1daeSBarry Smith M*/ 565c6c1daeSBarry Smith 57d71ae5a4SJacob Faibussowitsch PETSC_EXTERN PetscErrorCode PetscRandomCreate_Rand(PetscRandom r) 58d71ae5a4SJacob Faibussowitsch { 595c6c1daeSBarry Smith PetscFunctionBegin; 60aea10558SJacob Faibussowitsch r->ops[0] = PetscRandomOps_Values; 619566063dSJacob Faibussowitsch PetscCall(PetscObjectChangeTypeName((PetscObject)r, PETSCRAND)); 623ba16761SJacob Faibussowitsch PetscFunctionReturn(PETSC_SUCCESS); 635c6c1daeSBarry Smith } 64