xref: /petsc/src/sys/classes/random/tutorials/ex1.c (revision b122ec5aa1bd4469eb4e0673542fb7de3f411254)
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*b122ec5aSJacob Faibussowitsch   CHKERRQ(PetscInitialize(&argc,&argv,(char*)0,help));
245f80ce2aSJacob Faibussowitsch   CHKERRMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
255f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
265f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-view_randomvalues",&view_rank,NULL));
27c4762a1bSJed Brown 
285f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscRandomCreate(PETSC_COMM_WORLD,&rnd));
29c4762a1bSJed Brown   /* force imaginary part of random number to always be zero; thus obtain reproducible results with real and complex numbers */
305f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscRandomSetInterval(rnd,0.0,1.0));
315f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscRandomSetFromOptions(rnd));
32c4762a1bSJed Brown 
335f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscMalloc1(n,&values));
34c4762a1bSJed Brown   for (i=0; i<n; i++) {
355f80ce2aSJacob Faibussowitsch     CHKERRQ(PetscRandomGetValue(rnd,&value));
36c4762a1bSJed Brown     avg += value;
37c4762a1bSJed Brown     if (view_rank == (PetscInt)rank) {
385f80ce2aSJacob Faibussowitsch       CHKERRQ(PetscPrintf(PETSC_COMM_SELF,"[%d] value[%" PetscInt_FMT "] = %6.4e\n",rank,i,(double)PetscRealPart(value)));
39c4762a1bSJed Brown     }
40c4762a1bSJed Brown     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
41c4762a1bSJed Brown   }
42c4762a1bSJed Brown   avg = avg/((PetscReal)n);
43c4762a1bSJed Brown   if (view_rank == (PetscInt)rank) {
445f80ce2aSJacob Faibussowitsch     CHKERRQ(PetscPrintf(PETSC_COMM_SELF,"[%d] Average value %6.4e\n",rank,(double)PetscRealPart(avg)));
45c4762a1bSJed Brown   }
46c4762a1bSJed Brown 
475f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscSortInt(n,values));
48c4762a1bSJed Brown 
495f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscLogEventRegister("Sort",0,&event));
505f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscLogEventBegin(event,0,0,0,0));
51c4762a1bSJed Brown 
525f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscRandomSeed(rnd));
53c4762a1bSJed Brown   for (i=0; i<n; i++) {
545f80ce2aSJacob Faibussowitsch     CHKERRQ(PetscRandomGetValue(rnd,&value));
55c4762a1bSJed Brown     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
56c4762a1bSJed Brown     /* printf("value[%d] = %g\n",i,value); */
57c4762a1bSJed Brown   }
585f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscSortInt(n,values));
595f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscLogEventEnd(event,0,0,0,0));
60c4762a1bSJed Brown 
61c4762a1bSJed Brown   for (i=1; i<n; i++) {
622c71b3e2SJacob Faibussowitsch     PetscCheckFalse(values[i] < values[i-1],PETSC_COMM_SELF,PETSC_ERR_PLIB,"Values not sorted");
63c4762a1bSJed Brown   }
645f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscFree(values));
655f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscRandomDestroy(&rnd));
66c4762a1bSJed Brown 
67*b122ec5aSJacob Faibussowitsch   CHKERRQ(PetscFinalize());
68*b122ec5aSJacob Faibussowitsch   return 0;
69c4762a1bSJed Brown }
70c4762a1bSJed Brown 
71c4762a1bSJed Brown /*TEST
72c4762a1bSJed Brown 
73c4762a1bSJed Brown    test:
74c4762a1bSJed Brown 
75c4762a1bSJed Brown    test:
76c4762a1bSJed Brown       suffix: 2
77c4762a1bSJed Brown       nsize: 2
78c4762a1bSJed Brown       output_file: output/ex1_1.out
79c4762a1bSJed Brown 
80c4762a1bSJed Brown    test:
81c4762a1bSJed Brown       suffix: 3
82c4762a1bSJed Brown       args: -view_randomvalues 0
83c4762a1bSJed Brown 
84c4762a1bSJed Brown TEST*/
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