Actual source code: ex9.c
2: static char help[] = "Tests MPI parallel matrix creation.\n\n";
4: #include petscmat.h
8: int main(int argc,char **args)
9: {
10: Mat C;
11: MatInfo info;
12: PetscMPIInt rank,size;
13: PetscInt i,j,m = 3,n = 2,low,high,iglobal;
14: PetscInt Ii,J,ldim;
16: PetscTruth flg;
17: PetscScalar v,one = 1.0;
18: Vec u,b;
19: PetscInt bs,ndiag,diag[7]; bs = 1,ndiag = 5;
21: PetscInitialize(&argc,&args,(char *)0,help);
22: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
23: MPI_Comm_size(PETSC_COMM_WORLD,&size);
24: n = 2*size;
26: MatCreate(PETSC_COMM_WORLD,&C);
27: MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);
28: MatSetFromOptions(C);
30: diag[0] = n;
31: diag[1] = 1;
32: diag[2] = 0;
33: diag[3] = -1;
34: diag[4] = -n;
35: if (size>1) {ndiag = 7; diag[5] = 2; diag[6] = -2;}
37: /* Create the matrix for the five point stencil, YET AGAIN */
38: for (i=0; i<m; i++) {
39: for (j=2*rank; j<2*rank+2; j++) {
40: v = -1.0; Ii = j + n*i;
41: if (i>0) {J = Ii - n; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
42: if (i<m-1) {J = Ii + n; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
43: if (j>0) {J = Ii - 1; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
44: if (j<n-1) {J = Ii + 1; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
45: v = 4.0; MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES);
46: }
47: }
49: /* Add extra elements (to illustrate variants of MatGetInfo) */
50: Ii = n; J = n-2; v = 100.0;
51: MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);
52: Ii = n-2; J = n; v = 100.0;
53: MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);
55: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
56: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
58: /* Form vectors */
59: VecCreate(PETSC_COMM_WORLD,&u);
60: VecSetSizes(u,PETSC_DECIDE,m*n);
61: VecSetFromOptions(u);
62: VecDuplicate(u,&b);
63: VecGetLocalSize(u,&ldim);
64: VecGetOwnershipRange(u,&low,&high);
65: for (i=0; i<ldim; i++) {
66: iglobal = i + low;
67: v = one*((PetscReal)i) + 100.0*rank;
68: VecSetValues(u,1,&iglobal,&v,INSERT_VALUES);
69: }
70: VecAssemblyBegin(u);
71: VecAssemblyEnd(u);
73: MatMult(C,u,b);
75: VecView(u,PETSC_VIEWER_STDOUT_WORLD);
76: VecView(b,PETSC_VIEWER_STDOUT_WORLD);
78: VecDestroy(u);
79: VecDestroy(b);
81: PetscOptionsHasName(PETSC_NULL,"-view_info",&flg);
82: if (flg) {PetscViewerSetFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO);}
83: MatView(C,PETSC_VIEWER_STDOUT_WORLD);
85: MatGetInfo(C,MAT_GLOBAL_SUM,&info);
86: PetscPrintf(PETSC_COMM_WORLD,"matrix information (global sums):\n\
87: nonzeros = %D, allocated nonzeros = %D\n",(PetscInt)info.nz_used,(PetscInt)info.nz_allocated);
88: MatGetInfo (C,MAT_GLOBAL_MAX,&info);
89: PetscPrintf(PETSC_COMM_WORLD,"matrix information (global max):\n\
90: nonzeros = %D, allocated nonzeros = %D\n",(PetscInt)info.nz_used,(PetscInt)info.nz_allocated);
92: MatDestroy(C);
93: PetscFinalize();
94: return 0;
95: }