Actual source code: test6.c
slepc-3.7.2 2016-07-19
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-2016, Universitat Politecnica de Valencia, Spain
6: This file is part of SLEPc.
8: SLEPc is free software: you can redistribute it and/or modify it under the
9: terms of version 3 of the GNU Lesser General Public License as published by
10: the Free Software Foundation.
12: SLEPc is distributed in the hope that it will be useful, but WITHOUT ANY
13: WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14: FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
15: more details.
17: You should have received a copy of the GNU Lesser General Public License
18: along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
19: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
20: */
22: static char help[] = "Test BV orthogonalization functions with constraints.\n\n";
24: #include <slepcbv.h>
28: int main(int argc,char **argv)
29: {
31: BV X;
32: Mat M;
33: Vec v,t,*C;
34: PetscInt i,j,n=20,k=8,nc=2;
35: PetscViewer view;
36: PetscBool verbose;
37: PetscReal norm;
38: PetscScalar alpha;
40: SlepcInitialize(&argc,&argv,(char*)0,help);
41: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
42: PetscOptionsGetInt(NULL,NULL,"-k",&k,NULL);
43: PetscOptionsGetInt(NULL,NULL,"-nc",&nc,NULL);
44: PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
45: PetscPrintf(PETSC_COMM_WORLD,"Test BV orthogonalization with %D columns + %D constraints, of length %D.\n",k,nc,n);
47: /* Create template vector */
48: VecCreate(PETSC_COMM_WORLD,&t);
49: VecSetSizes(t,PETSC_DECIDE,n);
50: VecSetFromOptions(t);
52: /* Create BV object X */
53: BVCreate(PETSC_COMM_WORLD,&X);
54: PetscObjectSetName((PetscObject)X,"X");
55: BVSetSizesFromVec(X,t,k);
56: BVSetFromOptions(X);
58: /* Generate constraints and attach them to X */
59: if (nc>0) {
60: VecDuplicateVecs(t,nc,&C);
61: for (j=0;j<nc;j++) {
62: for (i=0;i<=j;i++) {
63: VecSetValue(C[j],i,1.0,INSERT_VALUES);
64: }
65: VecAssemblyBegin(C[j]);
66: VecAssemblyEnd(C[j]);
67: }
68: BVInsertConstraints(X,&nc,C);
69: VecDestroyVecs(nc,&C);
70: }
72: /* Set up viewer */
73: PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&view);
74: if (verbose) {
75: PetscViewerPushFormat(view,PETSC_VIEWER_ASCII_MATLAB);
76: }
78: /* Fill X entries */
79: for (j=0;j<k;j++) {
80: BVGetColumn(X,j,&v);
81: VecSet(v,0.0);
82: for (i=0;i<=n/2;i++) {
83: if (i+j<n) {
84: alpha = (3.0*i+j-2)/(2*(i+j+1));
85: VecSetValue(v,i+j,alpha,INSERT_VALUES);
86: }
87: }
88: VecAssemblyBegin(v);
89: VecAssemblyEnd(v);
90: BVRestoreColumn(X,j,&v);
91: }
92: if (verbose) {
93: BVView(X,view);
94: }
96: /* Test BVOrthogonalizeColumn */
97: for (j=0;j<k;j++) {
98: BVOrthogonalizeColumn(X,j,NULL,&norm,NULL);
99: alpha = 1.0/norm;
100: BVScaleColumn(X,j,alpha);
101: }
102: if (verbose) {
103: BVView(X,view);
104: }
106: /* Check orthogonality */
107: MatCreateSeqDense(PETSC_COMM_SELF,k,k,NULL,&M);
108: BVDot(X,X,M);
109: MatShift(M,-1.0);
110: MatNorm(M,NORM_1,&norm);
111: if (norm<100*PETSC_MACHINE_EPSILON) {
112: PetscPrintf(PETSC_COMM_WORLD,"Level of orthogonality < 100*eps\n");
113: } else {
114: PetscPrintf(PETSC_COMM_WORLD,"Level of orthogonality: %g\n",(double)norm);
115: }
117: MatDestroy(&M);
118: BVDestroy(&X);
119: VecDestroy(&t);
120: SlepcFinalize();
121: return ierr;
122: }