Actual source code: ex11.c
2: static char help[] = "Demonstrates VecStrideNorm().\n\n";
4: /*T
5: Concepts: vectors^norms of sub-vectors;
6: Processors: n
7: T*/
9: /*
10: Include "petscvec.h" so that we can use vectors. Note that this file
11: automatically includes:
12: petscsys.h - base PETSc routines petscis.h - index sets
13: petscviewer.h - viewers
14: */
16: #include <petscvec.h>
18: int main(int argc,char **argv)
19: {
20: Vec x; /* vectors */
21: PetscReal norm;
22: PetscInt n = 20;
23: PetscScalar one = 1.0;
25: PetscInitialize(&argc,&argv,(char*)0,help);
26: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
28: /*
29: Create a vector, specifying only its global dimension.
30: When using VecCreate(), VecSetSizes() and VecSetFromOptions(),
31: the vector format (currently parallel,
32: shared, or sequential) is determined at runtime. Also, the parallel
33: partitioning of the vector is determined by PETSc at runtime.
35: Routines for creating particular vector types directly are:
36: VecCreateSeq() - uniprocessor vector
37: VecCreateMPI() - distributed vector, where the user can
38: determine the parallel partitioning
39: VecCreateShared() - parallel vector that uses shared memory
40: (available only on the SGI); otherwise,
41: is the same as VecCreateMPI()
43: With VecCreate(), VecSetSizes() and VecSetFromOptions() the option
44: -vec_type mpi or -vec_type shared causes the
45: particular type of vector to be formed.
47: */
48: VecCreate(PETSC_COMM_WORLD,&x);
49: VecSetSizes(x,PETSC_DECIDE,n);
50: VecSetBlockSize(x,2);
51: VecSetFromOptions(x);
53: /*
54: Set the vectors to entries to a constant value.
55: */
56: VecSet(x,one);
58: VecNorm(x,NORM_2,&norm);
59: PetscPrintf(PETSC_COMM_WORLD,"L_2 Norm of entire vector: %g\n",(double)norm);
61: VecNorm(x,NORM_1,&norm);
62: PetscPrintf(PETSC_COMM_WORLD,"L_1 Norm of entire vector: %g\n",(double)norm);
64: VecNorm(x,NORM_INFINITY,&norm);
65: PetscPrintf(PETSC_COMM_WORLD,"L_inf Norm of entire vector: %g\n",(double)norm);
67: VecStrideNorm(x,0,NORM_2,&norm);
68: PetscPrintf(PETSC_COMM_WORLD,"L_2 Norm of sub-vector 0: %g\n",(double)norm);
70: VecStrideNorm(x,0,NORM_1,&norm);
71: PetscPrintf(PETSC_COMM_WORLD,"L_1 Norm of sub-vector 0: %g\n",(double)norm);
73: VecStrideNorm(x,0,NORM_INFINITY,&norm);
74: PetscPrintf(PETSC_COMM_WORLD,"L_inf Norm of sub-vector 0: %g\n",(double)norm);
76: VecStrideNorm(x,1,NORM_2,&norm);
77: PetscPrintf(PETSC_COMM_WORLD,"L_2 Norm of sub-vector 1: %g\n",(double)norm);
79: VecStrideNorm(x,1,NORM_1,&norm);
80: PetscPrintf(PETSC_COMM_WORLD,"L_1 Norm of sub-vector 1: %g\n",(double)norm);
82: VecStrideNorm(x,1,NORM_INFINITY,&norm);
83: PetscPrintf(PETSC_COMM_WORLD,"L_inf Norm of sub-vector 1: %g\n",(double)norm);
85: /*
86: Free work space. All PETSc objects should be destroyed when they
87: are no longer needed.
88: */
89: VecDestroy(&x);
90: PetscFinalize();
91: return 0;
92: }
94: /*TEST
96: test:
97: nsize: 2
99: TEST*/