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
main(int argc,char ** argv)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 == 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 == 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 output_file: output/empty.out
67
68 test:
69 suffix: 2
70 nsize: 2
71 output_file: output/empty.out
72
73 test:
74 suffix: 3
75 args: -view_randomvalues 0
76
77 TEST*/
78