Actual source code: test2.c
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-2012, Universitat Politecnica de Valencia, Spain
6: This file is part of SLEPc.
7:
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 DSHEP.\n\n";
24: #include slepcds.h
28: int main( int argc, char **argv )
29: {
31: DS ds;
32: PetscScalar *A,*eig;
33: PetscInt i,j,n=10,ld;
34: PetscViewer viewer;
35: PetscBool verbose,extrarow;
37: SlepcInitialize(&argc,&argv,(char*)0,help);
38: PetscOptionsGetInt(PETSC_NULL,"-n",&n,PETSC_NULL);
39: PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type HEP - dimension %D.\n",n);
40: PetscOptionsHasName(PETSC_NULL,"-verbose",&verbose);
41: PetscOptionsHasName(PETSC_NULL,"-extrarow",&extrarow);
43: /* Create DS object */
44: DSCreate(PETSC_COMM_WORLD,&ds);
45: DSSetType(ds,DSHEP);
46: DSSetFromOptions(ds);
47: ld = n+2; /* test leading dimension larger than n */
48: DSAllocate(ds,ld);
49: DSSetDimensions(ds,n,PETSC_IGNORE,0,0);
50: DSSetExtraRow(ds,extrarow);
52: /* Set up viewer */
53: PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
54: PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
55: DSView(ds,viewer);
56: PetscViewerPopFormat(viewer);
57: if (verbose) {
58: PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
59: }
61: /* Fill with a symmetric Toeplitz matrix */
62: DSGetArray(ds,DS_MAT_A,&A);
63: for (i=0;i<n;i++) A[i+i*ld]=2.0;
64: for (j=1;j<3;j++) {
65: for (i=0;i<n-j;i++) { A[i+(i+j)*ld]=1.0; A[(i+j)+i*ld]=1.0; }
66: }
67: if (extrarow) { A[n+(n-2)*ld]=1.0; A[n+(n-1)*ld]=1.0; }
68: DSRestoreArray(ds,DS_MAT_A,&A);
69: DSSetState(ds,DS_STATE_RAW);
70: if (verbose) {
71: PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
72: DSView(ds,viewer);
73: }
75: /* Solve */
76: PetscMalloc(n*sizeof(PetscScalar),&eig);
77: DSSetEigenvalueComparison(ds,SlepcCompareLargestMagnitude,PETSC_NULL);
78: DSSolve(ds,eig,PETSC_NULL);
79: DSSort(ds,eig,PETSC_NULL,PETSC_NULL,PETSC_NULL,PETSC_NULL);
80: if (extrarow) { DSUpdateExtraRow(ds); }
81: if (verbose) {
82: PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
83: DSView(ds,viewer);
84: }
86: /* Print eigenvalues */
87: PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n",n);
88: for (i=0;i<n;i++) {
89: PetscViewerASCIIPrintf(viewer," %.5F\n",PetscRealPart(eig[i]));
90: }
92: PetscFree(eig);
93: DSDestroy(&ds);
94: SlepcFinalize();
95: return 0;
96: }