Actual source code: ex36.c
petsc-3.4.2 2013-07-02
1: static char help[] = "Test MatGetInertia() for Hermitian matrix. \n\n";
2: /*
3: Example of usage
4: ./ex36 -check_Hermitian -display_mat -display_vec
5: mpiexec -n 2 ./ex36
7: This example is modified from src/mat/examples/tests/ex127.c
8: */
10: #include <petscksp.h>
14: PetscInt main(PetscInt argc,char **args)
15: {
16: Mat A,As;
17: PetscBool flg,disp_mat=PETSC_FALSE;
19: PetscMPIInt size,rank;
20: PetscInt i,j;
21: PetscScalar v,sigma2;
22: PetscRandom rctx;
23: PetscReal h2,sigma1=100.0;
24: PetscInt dim,Ii,J,n = 3,use_random,rstart,rend;
25: KSP ksp;
26: PC pc;
27: Mat F;
28: PetscInt nneg, nzero, npos;
30: PetscInitialize(&argc,&args,(char*)0,help);
31: #if !defined(PETSC_USE_COMPLEX)
32: SETERRQ(PETSC_COMM_WORLD,1,"This example requires complex numbers");
33: #endif
34: MPI_Comm_size(PETSC_COMM_WORLD,&size);
35: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
36: PetscOptionsHasName(NULL, "-display_mat", &disp_mat);
38: PetscOptionsGetReal(NULL,"-sigma1",&sigma1,NULL);
39: PetscOptionsGetInt(NULL,"-n",&n,NULL);
40: dim = n*n;
42: MatCreate(PETSC_COMM_WORLD,&A);
43: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,dim,dim);
44: MatSetType(A,MATAIJ);
45: MatSetFromOptions(A);
47: PetscOptionsHasName(NULL,"-norandom",&flg);
48: if (flg) use_random = 0;
49: else use_random = 1;
50: if (use_random) {
51: PetscRandomCreate(PETSC_COMM_WORLD,&rctx);
52: PetscRandomSetFromOptions(rctx);
53: PetscRandomSetInterval(rctx,0.0,PETSC_i);
54: PetscRandomGetValue(rctx,&sigma2); /* RealPart(sigma2) == 0.0 */
55: } else {
56: sigma2 = 10.0*PETSC_i;
57: }
58: h2 = 1.0/((n+1)*(n+1));
60: MatGetOwnershipRange(A,&rstart,&rend);
61: for (Ii=rstart; Ii<rend; Ii++) {
62: v = -1.0; i = Ii/n; j = Ii - i*n;
63: if (i>0) {
64: J = Ii-n; MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);
65: }
66: if (i<n-1) {
67: J = Ii+n; MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);
68: }
69: if (j>0) {
70: J = Ii-1; MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);
71: }
72: if (j<n-1) {
73: J = Ii+1; MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);
74: }
75: v = 4.0 - sigma1*h2;
76: MatSetValues(A,1,&Ii,1,&Ii,&v,ADD_VALUES);
77: }
78: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
79: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
81: /* Check whether A is symmetric */
82: PetscOptionsHasName(NULL, "-check_symmetric", &flg);
83: if (flg) {
84: Mat Trans;
85: MatTranspose(A,MAT_INITIAL_MATRIX, &Trans);
86: MatEqual(A, Trans, &flg);
87: if (!flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER,"A is not symmetric");
88: MatDestroy(&Trans);
89: }
90: MatSetOption(A,MAT_SYMMETRIC,PETSC_TRUE);
92: /* make A complex Hermitian */
93: Ii = 0; J = dim-1;
94: if (Ii >= rstart && Ii < rend) {
95: v = sigma2*h2; /* RealPart(v) = 0.0 */
96: MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);
97: v = -sigma2*h2;
98: MatSetValues(A,1,&J,1,&Ii,&v,ADD_VALUES);
99: }
101: Ii = dim-2; J = dim-1;
102: if (Ii >= rstart && Ii < rend) {
103: v = sigma2*h2; /* RealPart(v) = 0.0 */
104: MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);
105: v = -sigma2*h2;
106: MatSetValues(A,1,&J,1,&Ii,&v,ADD_VALUES);
107: }
109: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
110: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
112: /* Check whether A is Hermitian */
113: PetscOptionsHasName(NULL, "-check_Hermitian", &flg);
114: if (flg) {
115: Mat Hermit;
116: if (disp_mat) {
117: if (!rank) printf(" A:\n");
118: MatView(A,PETSC_VIEWER_STDOUT_WORLD);
119: }
120: MatHermitianTranspose(A,MAT_INITIAL_MATRIX, &Hermit);
121: if (disp_mat) {
122: if (!rank) printf(" A_Hermitian:\n");
123: MatView(Hermit,PETSC_VIEWER_STDOUT_WORLD);
124: }
125: MatEqual(A, Hermit, &flg);
126: if (!flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER,"A is not Hermitian");
127: MatDestroy(&Hermit);
128: }
129: MatSetOption(A,MAT_HERMITIAN,PETSC_TRUE);
131: /* Create a Hermitian matrix As in sbaij format */
132: MatConvert(A,MATSBAIJ,MAT_INITIAL_MATRIX,&As);
133: if (disp_mat) {
134: if (!rank) {PetscPrintf(PETSC_COMM_SELF," As:\n");}
135: MatView(As,PETSC_VIEWER_STDOUT_WORLD);
136: }
138: /* Test MatGetInertia() */
139: KSPCreate(PETSC_COMM_WORLD,&ksp);
140: KSPSetType(ksp,KSPPREONLY);
141: KSPSetOperators(ksp,As,As,DIFFERENT_NONZERO_PATTERN);
143: KSPGetPC(ksp,&pc);
144: PCSetType(pc,PCCHOLESKY);
145: PCSetFromOptions(pc);
147: PCSetUp(pc);
148: PCFactorGetMatrix(pc,&F);
149: MatGetInertia(F,&nneg,&nzero,&npos);
150: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
151: if (!rank) {
152: PetscPrintf(PETSC_COMM_SELF," MatInertia: nneg: %D, nzero: %D, npos: %D\n",nneg,nzero,npos);
153: }
155: /* Free spaces */
156: KSPDestroy(&ksp);
157: if (use_random) {PetscRandomDestroy(&rctx);}
158: MatDestroy(&A);
159: MatDestroy(&As);
160: PetscFinalize();
161: return 0;
162: }