1 2 #include <petsc/private/randomimpl.h> 3 4 PetscErrorCode PetscRandomSeed_Rand(PetscRandom r) 5 { 6 PetscFunctionBegin; 7 srand(r->seed); 8 PetscFunctionReturn(0); 9 } 10 11 #define RAND_WRAP ((PetscReal)((rand()/(double)((unsigned int)RAND_MAX+1)))) 12 PetscErrorCode PetscRandomGetValue_Rand(PetscRandom r,PetscScalar *val) 13 { 14 PetscFunctionBegin; 15 #if defined(PETSC_USE_COMPLEX) 16 if (r->iset) *val = PetscRealPart(r->width)*RAND_WRAP + PetscRealPart(r->low) + (PetscImaginaryPart(r->width)*RAND_WRAP + PetscImaginaryPart(r->low)) * PETSC_i; 17 else *val = RAND_WRAP + RAND_WRAP*PETSC_i; 18 #else 19 if (r->iset) *val = r->width * RAND_WRAP + r->low; 20 else *val = RAND_WRAP; 21 #endif 22 PetscFunctionReturn(0); 23 } 24 25 PetscErrorCode PetscRandomGetValueReal_Rand(PetscRandom r,PetscReal *val) 26 { 27 PetscFunctionBegin; 28 #if defined(PETSC_USE_COMPLEX) 29 if (r->iset) *val = PetscRealPart(r->width)*RAND_WRAP + PetscRealPart(r->low); 30 else *val = RAND_WRAP; 31 #else 32 if (r->iset) *val = r->width * RAND_WRAP + r->low; 33 else *val = RAND_WRAP; 34 #endif 35 PetscFunctionReturn(0); 36 } 37 38 static struct _PetscRandomOps PetscRandomOps_Values = { 39 PetscRandomSeed_Rand, 40 PetscRandomGetValue_Rand, 41 PetscRandomGetValueReal_Rand, 42 NULL, 43 NULL, 44 NULL, 45 NULL 46 }; 47 48 /*MC 49 PETSCRAND - access to the basic Unix random number generator 50 51 Options Database Keys: 52 . -random_type <rand,rand48,sprng> 53 54 Level: beginner 55 56 .seealso: PetscRandomCreate(), PetscRandomSetType(), PETSCRAND48, PETSCSPRNG 57 M*/ 58 59 PETSC_EXTERN PetscErrorCode PetscRandomCreate_Rand(PetscRandom r) 60 { 61 PetscErrorCode ierr; 62 63 PetscFunctionBegin; 64 ierr = PetscMemcpy(r->ops,&PetscRandomOps_Values,sizeof(PetscRandomOps_Values));CHKERRQ(ierr); 65 ierr = PetscObjectChangeTypeName((PetscObject)r,PETSCRAND);CHKERRQ(ierr); 66 PetscFunctionReturn(0); 67 } 68