10039db0dSBarry Smith #define PETSC_DESIRE_FEATURE_TEST_MACROS /* for drand48() */ 2d6cc7855SJacob Faibussowitsch #include <petsc/private/randomimpl.h> 35c6c1daeSBarry Smith 45c6c1daeSBarry Smith PetscErrorCode PetscRandomSeed_Rand48(PetscRandom r) 55c6c1daeSBarry Smith { 65c6c1daeSBarry Smith PetscFunctionBegin; 75c6c1daeSBarry Smith srand48(r->seed); 85c6c1daeSBarry Smith PetscFunctionReturn(0); 95c6c1daeSBarry Smith } 105c6c1daeSBarry Smith 115c6c1daeSBarry Smith PetscErrorCode PetscRandomGetValue_Rand48(PetscRandom r,PetscScalar *val) 125c6c1daeSBarry Smith { 135c6c1daeSBarry Smith PetscFunctionBegin; 145c6c1daeSBarry Smith #if defined(PETSC_USE_COMPLEX) 155c6c1daeSBarry Smith if (r->iset) { 16b0043f70SBarry Smith *val = PetscRealPart(r->width)*(PetscReal)drand48() + PetscRealPart(r->low) + (PetscImaginaryPart(r->width)*(PetscReal)drand48() + PetscImaginaryPart(r->low)) * PETSC_i; 175c6c1daeSBarry Smith } else { 185c6c1daeSBarry Smith *val = (PetscReal)drand48() + (PetscReal)drand48()*PETSC_i; 195c6c1daeSBarry Smith } 205c6c1daeSBarry Smith #else 215c6c1daeSBarry Smith if (r->iset) *val = r->width * drand48() + r->low; 225c6c1daeSBarry Smith else *val = drand48(); 235c6c1daeSBarry Smith #endif 245c6c1daeSBarry Smith PetscFunctionReturn(0); 255c6c1daeSBarry Smith } 265c6c1daeSBarry Smith 275c6c1daeSBarry Smith PetscErrorCode PetscRandomGetValueReal_Rand48(PetscRandom r,PetscReal *val) 285c6c1daeSBarry Smith { 295c6c1daeSBarry Smith PetscFunctionBegin; 305c6c1daeSBarry Smith #if defined(PETSC_USE_COMPLEX) 315c6c1daeSBarry Smith if (r->iset) *val = PetscRealPart(r->width)*drand48() + PetscRealPart(r->low); 325c6c1daeSBarry Smith else *val = drand48(); 335c6c1daeSBarry Smith #else 345c6c1daeSBarry Smith if (r->iset) *val = r->width * drand48() + r->low; 355c6c1daeSBarry Smith else *val = drand48(); 365c6c1daeSBarry Smith #endif 375c6c1daeSBarry Smith PetscFunctionReturn(0); 385c6c1daeSBarry Smith } 395c6c1daeSBarry Smith 405c6c1daeSBarry Smith static struct _PetscRandomOps PetscRandomOps_Values = { 41267267bdSJacob Faibussowitsch PetscDesignatedInitializer(seed,PetscRandomSeed_Rand48), 42267267bdSJacob Faibussowitsch PetscDesignatedInitializer(getvalue,PetscRandomGetValue_Rand48), 43267267bdSJacob Faibussowitsch PetscDesignatedInitializer(getvaluereal,PetscRandomGetValueReal_Rand48), 445c6c1daeSBarry Smith }; 455c6c1daeSBarry Smith 465c6c1daeSBarry Smith /*MC 475c6c1daeSBarry Smith PETSCRAND48 - access to the basic Unix drand48() random number generator 485c6c1daeSBarry Smith 495c6c1daeSBarry Smith Options Database Keys: 50*1179163eSBarry Smith . -random_type <rand,rand48,sprng> - select the random number generator at runtime 515c6c1daeSBarry Smith 525c6c1daeSBarry Smith Level: beginner 535c6c1daeSBarry Smith 54*1179163eSBarry Smith Notes: 55*1179163eSBarry Smith Not recommended because it may produce different results on different systems. 56*1179163eSBarry Smith 57*1179163eSBarry Smith .seealso: `PetscRandomCreate()`, `PetscRandomSetType()`, `PETSCRAND`, `PETSCSPRNG`, `PetscRandomSetFromOptions()` 585c6c1daeSBarry Smith M*/ 595c6c1daeSBarry Smith 608cc058d9SJed Brown PETSC_EXTERN PetscErrorCode PetscRandomCreate_Rand48(PetscRandom r) 615c6c1daeSBarry Smith { 625c6c1daeSBarry Smith PetscFunctionBegin; 639566063dSJacob Faibussowitsch PetscCall(PetscMemcpy(r->ops,&PetscRandomOps_Values,sizeof(PetscRandomOps_Values))); 649566063dSJacob Faibussowitsch PetscCall(PetscObjectChangeTypeName((PetscObject)r,PETSCRAND48)); 655c6c1daeSBarry Smith PetscFunctionReturn(0); 665c6c1daeSBarry Smith } 67