Actual source code: test13.c
slepc-3.11.2 2019-07-30
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-2019, Universitat Politecnica de Valencia, Spain
6: This file is part of SLEPc.
7: SLEPc is distributed under a 2-clause BSD license (see LICENSE).
8: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
9: */
11: static char help[] = "Test DSHEP with block size larger than one.\n\n";
13: #include <slepcds.h>
15: int main(int argc,char **argv)
16: {
18: DS ds;
19: SlepcSC sc;
20: PetscScalar *A,*eig;
21: PetscInt i,j,n,ld,bs,maxbw=3,nblks=8;
22: PetscViewer viewer;
23: PetscBool verbose;
25: SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
26: PetscOptionsGetInt(NULL,NULL,"-maxbw",&maxbw,NULL);
27: PetscOptionsGetInt(NULL,NULL,"-nblks",&nblks,NULL);
28: n = maxbw*nblks;
29: bs = maxbw;
30: PetscPrintf(PETSC_COMM_WORLD,"Solve a block HEP Dense System - dimension %D (bandwidth=%D, blocks=%D).\n",n,maxbw,nblks);
31: PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
33: /* Create DS object */
34: DSCreate(PETSC_COMM_WORLD,&ds);
35: DSSetType(ds,DSHEP);
36: DSSetMethod(ds,3); /* Select block divide-and-conquer */
37: DSSetBlockSize(ds,bs);
38: DSSetFromOptions(ds);
39: ld = n;
40: DSAllocate(ds,ld);
41: DSSetDimensions(ds,n,0,0,0);
43: /* Set up viewer */
44: PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
45: PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
46: DSView(ds,viewer);
47: PetscViewerPopFormat(viewer);
48: if (verbose) {
49: PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
50: }
52: /* Fill with a symmetric band Toeplitz matrix */
53: DSGetArray(ds,DS_MAT_A,&A);
54: for (i=0;i<n;i++) A[i+i*ld]=2.0;
55: for (j=1;j<=bs;j++) {
56: for (i=0;i<n-j;i++) { A[i+(i+j)*ld]=1.0; A[(i+j)+i*ld]=1.0; }
57: }
58: DSRestoreArray(ds,DS_MAT_A,&A);
59: DSSetState(ds,DS_STATE_RAW);
60: if (verbose) {
61: PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
62: DSView(ds,viewer);
63: }
65: /* Solve */
66: PetscMalloc1(n,&eig);
67: DSGetSlepcSC(ds,&sc);
68: sc->comparison = SlepcCompareSmallestReal;
69: sc->comparisonctx = NULL;
70: sc->map = NULL;
71: sc->mapobj = NULL;
72: DSSolve(ds,eig,NULL);
73: DSSort(ds,eig,NULL,NULL,NULL,NULL);
74: if (verbose) {
75: PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
76: DSView(ds,viewer);
77: }
79: /* Print eigenvalues */
80: PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
81: for (i=0;i<n;i++) {
82: PetscViewerASCIIPrintf(viewer," %.5f\n",(double)PetscRealPart(eig[i]));
83: }
85: PetscFree(eig);
86: DSDestroy(&ds);
87: SlepcFinalize();
88: return ierr;
89: }
91: /*TEST
93: test:
94: suffix: 1
95: requires: !complex !single
97: TEST*/