1 static char help[] = "Tests PetscRandom functions.\n\n"; 2 3 #include <petscsys.h> 4 5 /* Usage: 6 mpiexec -n <np> ./ex1 -n <num_of_random_numbers> -random_type <type> -log_view 7 -view_randomvalues <view_rank> 8 -random_view ascii -random_view :filename 9 */ 10 11 int main(int argc, char **argv) 12 { 13 PetscInt i, n = 1000, *values; 14 PetscRandom rnd; 15 PetscScalar value, avg = 0.0; 16 PetscMPIInt rank; 17 PetscInt view_rank = -1; 18 PetscLogEvent event; 19 20 PetscFunctionBeginUser; 21 PetscCall(PetscInitialize(&argc, &argv, NULL, help)); 22 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 23 PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL)); 24 PetscCall(PetscOptionsGetInt(NULL, NULL, "-view_randomvalues", &view_rank, NULL)); 25 26 PetscCall(PetscRandomCreate(PETSC_COMM_WORLD, &rnd)); 27 /* force imaginary part of random number to always be zero; thus obtain reproducible results with real and complex numbers */ 28 PetscCall(PetscRandomSetInterval(rnd, 0.0, 1.0)); 29 PetscCall(PetscRandomSetFromOptions(rnd)); 30 31 PetscCall(PetscMalloc1(n, &values)); 32 for (i = 0; i < n; i++) { 33 PetscCall(PetscRandomGetValue(rnd, &value)); 34 avg += value; 35 if (view_rank == (PetscInt)rank) PetscCall(PetscPrintf(PETSC_COMM_SELF, "[%d] value[%" PetscInt_FMT "] = %6.4e\n", rank, i, (double)PetscRealPart(value))); 36 values[i] = (PetscInt)(n * PetscRealPart(value) + 2.0); 37 } 38 avg = avg / ((PetscReal)n); 39 if (view_rank == (PetscInt)rank) PetscCall(PetscPrintf(PETSC_COMM_SELF, "[%d] Average value %6.4e\n", rank, (double)PetscRealPart(avg))); 40 41 PetscCall(PetscSortInt(n, values)); 42 43 PetscCall(PetscLogEventRegister("Sort", 0, &event)); 44 PetscCall(PetscLogEventBegin(event, 0, 0, 0, 0)); 45 46 PetscCall(PetscRandomSeed(rnd)); 47 for (i = 0; i < n; i++) { 48 PetscCall(PetscRandomGetValue(rnd, &value)); 49 values[i] = (PetscInt)(n * PetscRealPart(value) + 2.0); 50 /* printf("value[%d] = %g\n",i,value); */ 51 } 52 PetscCall(PetscSortInt(n, values)); 53 PetscCall(PetscLogEventEnd(event, 0, 0, 0, 0)); 54 55 for (i = 1; i < n; i++) PetscCheck(values[i] >= values[i - 1], PETSC_COMM_SELF, PETSC_ERR_PLIB, "Values not sorted"); 56 PetscCall(PetscFree(values)); 57 PetscCall(PetscRandomDestroy(&rnd)); 58 59 PetscCall(PetscFinalize()); 60 return 0; 61 } 62 63 /*TEST 64 65 test: 66 67 test: 68 suffix: 2 69 nsize: 2 70 output_file: output/ex1_1.out 71 72 test: 73 suffix: 3 74 args: -view_randomvalues 0 75 76 TEST*/ 77