Actual source code: test13.c
slepc-3.18.3 2023-03-24
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-, 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: {
17: DS ds;
18: SlepcSC sc;
19: PetscScalar *A,*eig;
20: PetscInt i,j,n,ld,bs,maxbw=3,nblks=8;
21: PetscViewer viewer;
22: PetscBool verbose;
25: SlepcInitialize(&argc,&argv,(char*)0,help);
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 %" PetscInt_FMT " (bandwidth=%" PetscInt_FMT ", blocks=%" PetscInt_FMT ").\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);
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) PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
50: /* Fill with a symmetric band Toeplitz matrix */
51: DSGetArray(ds,DS_MAT_A,&A);
52: for (i=0;i<n;i++) A[i+i*ld]=2.0;
53: for (j=1;j<=bs;j++) {
54: for (i=0;i<n-j;i++) { A[i+(i+j)*ld]=1.0; A[(i+j)+i*ld]=1.0; }
55: }
56: DSRestoreArray(ds,DS_MAT_A,&A);
57: DSSetState(ds,DS_STATE_RAW);
58: if (verbose) {
59: PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
60: DSView(ds,viewer);
61: }
63: /* Solve */
64: PetscMalloc1(n,&eig);
65: DSGetSlepcSC(ds,&sc);
66: sc->comparison = SlepcCompareSmallestReal;
67: sc->comparisonctx = NULL;
68: sc->map = NULL;
69: sc->mapobj = NULL;
70: DSSolve(ds,eig,NULL);
71: DSSort(ds,eig,NULL,NULL,NULL,NULL);
72: if (verbose) {
73: PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
74: DSView(ds,viewer);
75: }
77: /* Print eigenvalues */
78: PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
79: for (i=0;i<n;i++) PetscViewerASCIIPrintf(viewer," %.5f\n",(double)PetscRealPart(eig[i]));
81: PetscFree(eig);
82: DSDestroy(&ds);
83: SlepcFinalize();
84: return 0;
85: }
87: /*TEST
89: test:
90: suffix: 1
91: requires: !complex !single
93: test:
94: suffix: 2
95: args: -nblks 1
96: requires: !complex
98: TEST*/