xref: /petsc/src/sys/classes/random/tutorials/ex1.c (revision 327415f76d85372a4417cf1aaa14db707d4d6c04)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Tests PetscRandom functions.\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown #include <petscsys.h>
5c4762a1bSJed Brown 
6c4762a1bSJed Brown /* Usage:
7c4762a1bSJed Brown    mpiexec -n <np> ./ex1 -n <num_of_random_numbers> -random_type <type> -log_view
8c4762a1bSJed Brown                          -view_randomvalues <view_rank>
9c4762a1bSJed Brown                          -random_view ascii -random_view :filename
10c4762a1bSJed Brown */
11c4762a1bSJed Brown 
12c4762a1bSJed Brown int main(int argc,char **argv)
13c4762a1bSJed Brown {
14c4762a1bSJed Brown   PetscInt       i,n = 1000,*values;
15c4762a1bSJed Brown   PetscRandom    rnd;
16c4762a1bSJed Brown   PetscScalar    value,avg = 0.0;
17c4762a1bSJed Brown   PetscMPIInt    rank;
18c4762a1bSJed Brown   PetscInt       view_rank=-1;
19c4762a1bSJed Brown #if defined(PETSC_USE_LOG)
20c4762a1bSJed Brown   PetscLogEvent  event;
21c4762a1bSJed Brown #endif
22c4762a1bSJed Brown 
23*327415f7SBarry Smith   PetscFunctionBeginUser;
249566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
259566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
269566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
279566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL,NULL,"-view_randomvalues",&view_rank,NULL));
28c4762a1bSJed Brown 
299566063dSJacob Faibussowitsch   PetscCall(PetscRandomCreate(PETSC_COMM_WORLD,&rnd));
30c4762a1bSJed Brown   /* force imaginary part of random number to always be zero; thus obtain reproducible results with real and complex numbers */
319566063dSJacob Faibussowitsch   PetscCall(PetscRandomSetInterval(rnd,0.0,1.0));
329566063dSJacob Faibussowitsch   PetscCall(PetscRandomSetFromOptions(rnd));
33c4762a1bSJed Brown 
349566063dSJacob Faibussowitsch   PetscCall(PetscMalloc1(n,&values));
35c4762a1bSJed Brown   for (i=0; i<n; i++) {
369566063dSJacob Faibussowitsch     PetscCall(PetscRandomGetValue(rnd,&value));
37c4762a1bSJed Brown     avg += value;
38c4762a1bSJed Brown     if (view_rank == (PetscInt)rank) {
399566063dSJacob Faibussowitsch       PetscCall(PetscPrintf(PETSC_COMM_SELF,"[%d] value[%" PetscInt_FMT "] = %6.4e\n",rank,i,(double)PetscRealPart(value)));
40c4762a1bSJed Brown     }
41c4762a1bSJed Brown     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
42c4762a1bSJed Brown   }
43c4762a1bSJed Brown   avg = avg/((PetscReal)n);
44c4762a1bSJed Brown   if (view_rank == (PetscInt)rank) {
459566063dSJacob Faibussowitsch     PetscCall(PetscPrintf(PETSC_COMM_SELF,"[%d] Average value %6.4e\n",rank,(double)PetscRealPart(avg)));
46c4762a1bSJed Brown   }
47c4762a1bSJed Brown 
489566063dSJacob Faibussowitsch   PetscCall(PetscSortInt(n,values));
49c4762a1bSJed Brown 
509566063dSJacob Faibussowitsch   PetscCall(PetscLogEventRegister("Sort",0,&event));
519566063dSJacob Faibussowitsch   PetscCall(PetscLogEventBegin(event,0,0,0,0));
52c4762a1bSJed Brown 
539566063dSJacob Faibussowitsch   PetscCall(PetscRandomSeed(rnd));
54c4762a1bSJed Brown   for (i=0; i<n; i++) {
559566063dSJacob Faibussowitsch     PetscCall(PetscRandomGetValue(rnd,&value));
56c4762a1bSJed Brown     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
57c4762a1bSJed Brown     /* printf("value[%d] = %g\n",i,value); */
58c4762a1bSJed Brown   }
599566063dSJacob Faibussowitsch   PetscCall(PetscSortInt(n,values));
609566063dSJacob Faibussowitsch   PetscCall(PetscLogEventEnd(event,0,0,0,0));
61c4762a1bSJed Brown 
62c4762a1bSJed Brown   for (i=1; i<n; i++) {
6308401ef6SPierre Jolivet     PetscCheck(values[i] >= values[i-1],PETSC_COMM_SELF,PETSC_ERR_PLIB,"Values not sorted");
64c4762a1bSJed Brown   }
659566063dSJacob Faibussowitsch   PetscCall(PetscFree(values));
669566063dSJacob Faibussowitsch   PetscCall(PetscRandomDestroy(&rnd));
67c4762a1bSJed Brown 
689566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
69b122ec5aSJacob Faibussowitsch   return 0;
70c4762a1bSJed Brown }
71c4762a1bSJed Brown 
72c4762a1bSJed Brown /*TEST
73c4762a1bSJed Brown 
74c4762a1bSJed Brown    test:
75c4762a1bSJed Brown 
76c4762a1bSJed Brown    test:
77c4762a1bSJed Brown       suffix: 2
78c4762a1bSJed Brown       nsize: 2
79c4762a1bSJed Brown       output_file: output/ex1_1.out
80c4762a1bSJed Brown 
81c4762a1bSJed Brown    test:
82c4762a1bSJed Brown       suffix: 3
83c4762a1bSJed Brown       args: -view_randomvalues 0
84c4762a1bSJed Brown 
85c4762a1bSJed Brown TEST*/
86