xref: /petsc/src/sys/classes/random/tutorials/ex1.c (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
1*c4762a1bSJed Brown 
2*c4762a1bSJed Brown static char help[] = "Tests PetscRandom functions.\n\n";
3*c4762a1bSJed Brown 
4*c4762a1bSJed Brown #include <petscsys.h>
5*c4762a1bSJed Brown 
6*c4762a1bSJed Brown /* Usage:
7*c4762a1bSJed Brown    mpiexec -n <np> ./ex1 -n <num_of_random_numbers> -random_type <type> -log_view
8*c4762a1bSJed Brown                          -view_randomvalues <view_rank>
9*c4762a1bSJed Brown                          -random_view ascii -random_view :filename
10*c4762a1bSJed Brown */
11*c4762a1bSJed Brown 
12*c4762a1bSJed Brown int main(int argc,char **argv)
13*c4762a1bSJed Brown {
14*c4762a1bSJed Brown   PetscInt       i,n = 1000,*values;
15*c4762a1bSJed Brown   PetscRandom    rnd;
16*c4762a1bSJed Brown   PetscScalar    value,avg = 0.0;
17*c4762a1bSJed Brown   PetscErrorCode ierr;
18*c4762a1bSJed Brown   PetscMPIInt    rank;
19*c4762a1bSJed Brown   PetscInt       view_rank=-1;
20*c4762a1bSJed Brown #if defined(PETSC_USE_LOG)
21*c4762a1bSJed Brown   PetscLogEvent  event;
22*c4762a1bSJed Brown #endif
23*c4762a1bSJed Brown 
24*c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
25*c4762a1bSJed Brown   ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
26*c4762a1bSJed Brown   ierr = PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);CHKERRQ(ierr);
27*c4762a1bSJed Brown   ierr = PetscOptionsGetInt(NULL,NULL,"-view_randomvalues",&view_rank,NULL);CHKERRQ(ierr);
28*c4762a1bSJed Brown 
29*c4762a1bSJed Brown   ierr = PetscRandomCreate(PETSC_COMM_WORLD,&rnd);CHKERRQ(ierr);
30*c4762a1bSJed Brown   /* force imaginary part of random number to always be zero; thus obtain reproducible results with real and complex numbers */
31*c4762a1bSJed Brown   ierr = PetscRandomSetInterval(rnd,0.0,1.0);CHKERRQ(ierr);
32*c4762a1bSJed Brown   ierr = PetscRandomSetFromOptions(rnd);CHKERRQ(ierr);
33*c4762a1bSJed Brown 
34*c4762a1bSJed Brown   ierr = PetscMalloc1(n,&values);CHKERRQ(ierr);
35*c4762a1bSJed Brown   for (i=0; i<n; i++) {
36*c4762a1bSJed Brown     ierr = PetscRandomGetValue(rnd,&value);CHKERRQ(ierr);
37*c4762a1bSJed Brown     avg += value;
38*c4762a1bSJed Brown     if (view_rank == (PetscInt)rank) {
39*c4762a1bSJed Brown       ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] value[%D] = %6.4e\n",rank,i,(double)PetscRealPart(value));CHKERRQ(ierr);
40*c4762a1bSJed Brown     }
41*c4762a1bSJed Brown     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
42*c4762a1bSJed Brown   }
43*c4762a1bSJed Brown   avg = avg/((PetscReal)n);
44*c4762a1bSJed Brown   if (view_rank == (PetscInt)rank) {
45*c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] Average value %6.4e\n",rank,(double)PetscRealPart(avg));CHKERRQ(ierr);
46*c4762a1bSJed Brown   }
47*c4762a1bSJed Brown 
48*c4762a1bSJed Brown   ierr = PetscSortInt(n,values);CHKERRQ(ierr);
49*c4762a1bSJed Brown 
50*c4762a1bSJed Brown   ierr = PetscLogEventRegister("Sort",0,&event);CHKERRQ(ierr);
51*c4762a1bSJed Brown   ierr = PetscLogEventBegin(event,0,0,0,0);CHKERRQ(ierr);
52*c4762a1bSJed Brown 
53*c4762a1bSJed Brown   ierr = PetscRandomSeed(rnd);CHKERRQ(ierr);
54*c4762a1bSJed Brown   for (i=0; i<n; i++) {
55*c4762a1bSJed Brown     ierr      = PetscRandomGetValue(rnd,&value);CHKERRQ(ierr);
56*c4762a1bSJed Brown     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
57*c4762a1bSJed Brown     /* printf("value[%d] = %g\n",i,value); */
58*c4762a1bSJed Brown   }
59*c4762a1bSJed Brown   ierr = PetscSortInt(n,values);CHKERRQ(ierr);
60*c4762a1bSJed Brown   ierr = PetscLogEventEnd(event,0,0,0,0);CHKERRQ(ierr);
61*c4762a1bSJed Brown 
62*c4762a1bSJed Brown   for (i=1; i<n; i++) {
63*c4762a1bSJed Brown     if (values[i] < values[i-1]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Values not sorted");
64*c4762a1bSJed Brown   }
65*c4762a1bSJed Brown   ierr = PetscFree(values);CHKERRQ(ierr);
66*c4762a1bSJed Brown   ierr = PetscRandomDestroy(&rnd);CHKERRQ(ierr);
67*c4762a1bSJed Brown 
68*c4762a1bSJed Brown   ierr = PetscFinalize();
69*c4762a1bSJed Brown   return ierr;
70*c4762a1bSJed Brown }
71*c4762a1bSJed Brown 
72*c4762a1bSJed Brown 
73*c4762a1bSJed Brown 
74*c4762a1bSJed Brown /*TEST
75*c4762a1bSJed Brown 
76*c4762a1bSJed Brown    test:
77*c4762a1bSJed Brown 
78*c4762a1bSJed Brown    test:
79*c4762a1bSJed Brown       suffix: 2
80*c4762a1bSJed Brown       nsize: 2
81*c4762a1bSJed Brown       output_file: output/ex1_1.out
82*c4762a1bSJed Brown 
83*c4762a1bSJed Brown    test:
84*c4762a1bSJed Brown       suffix: 3
85*c4762a1bSJed Brown       args: -view_randomvalues 0
86*c4762a1bSJed Brown 
87*c4762a1bSJed Brown TEST*/
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