Actual source code: test8.c
slepc-3.18.2 2023-01-26
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 DSSVD with compact storage.\n\n";
13: #include <slepcds.h>
15: int main(int argc,char **argv)
16: {
17: DS ds;
18: SlepcSC sc;
19: PetscReal *T,sigma;
20: PetscScalar *U,*w,d;
21: PetscInt i,n=10,m,l=2,k=5,ld;
22: PetscViewer viewer;
23: PetscBool verbose,extrarow;
26: SlepcInitialize(&argc,&argv,(char*)0,help);
27: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
28: m = n;
29: PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type SVD with compact storage - dimension %" PetscInt_FMT "x%" PetscInt_FMT ".\n",n,m);
30: PetscOptionsGetInt(NULL,NULL,"-l",&l,NULL);
31: PetscOptionsGetInt(NULL,NULL,"-k",&k,NULL);
33: PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
34: PetscOptionsHasName(NULL,NULL,"-extrarow",&extrarow);
36: /* Create DS object */
37: DSCreate(PETSC_COMM_WORLD,&ds);
38: DSSetType(ds,DSSVD);
39: DSSetFromOptions(ds);
40: ld = n+2; /* test leading dimension larger than n */
41: DSAllocate(ds,ld);
42: DSSetDimensions(ds,n,l,k);
43: DSSVDSetDimensions(ds,m);
44: DSSetCompact(ds,PETSC_TRUE);
45: DSSetExtraRow(ds,extrarow);
47: /* Set up viewer */
48: PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
49: PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
50: DSView(ds,viewer);
51: PetscViewerPopFormat(viewer);
52: PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
54: /* Fill upper arrow-bidiagonal matrix */
55: DSGetArrayReal(ds,DS_MAT_T,&T);
56: for (i=0;i<n;i++) T[i] = (PetscReal)(i+1);
57: for (i=l;i<n-1;i++) T[i+ld] = 1.0;
58: if (extrarow) T[n-1+ld] = 1.0;
59: DSRestoreArrayReal(ds,DS_MAT_T,&T);
60: if (l==0 && k==0) DSSetState(ds,DS_STATE_INTERMEDIATE);
61: else DSSetState(ds,DS_STATE_RAW);
62: PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
63: DSView(ds,viewer);
65: /* Solve */
66: PetscMalloc1(n,&w);
67: DSGetSlepcSC(ds,&sc);
68: sc->comparison = SlepcCompareLargestReal;
69: sc->comparisonctx = NULL;
70: sc->map = NULL;
71: sc->mapobj = NULL;
72: DSSolve(ds,w,NULL);
73: DSSort(ds,w,NULL,NULL,NULL,NULL);
74: if (extrarow) DSUpdateExtraRow(ds);
75: if (verbose) {
76: PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
77: DSView(ds,viewer);
78: }
80: /* Print singular values */
81: PetscPrintf(PETSC_COMM_WORLD,"Computed singular values =\n");
82: for (i=0;i<n;i++) {
83: sigma = PetscRealPart(w[i]);
84: PetscViewerASCIIPrintf(viewer," %.5f\n",(double)sigma);
85: }
87: if (extrarow) {
88: /* Check that extra row is correct */
89: DSGetArrayReal(ds,DS_MAT_T,&T);
90: DSGetArray(ds,DS_MAT_U,&U);
91: d = 0.0;
92: for (i=l;i<n;i++) d += T[i+ld]-U[n-1+i*ld];
93: if (PetscAbsScalar(d)>10*PETSC_MACHINE_EPSILON) PetscPrintf(PETSC_COMM_WORLD,"Warning: there is a mismatch in the extra row of %g\n",(double)PetscAbsScalar(d));
94: DSRestoreArrayReal(ds,DS_MAT_T,&T);
95: DSRestoreArray(ds,DS_MAT_U,&U);
96: }
97: PetscFree(w);
98: DSDestroy(&ds);
99: SlepcFinalize();
100: return 0;
101: }
103: /*TEST
105: test:
106: suffix: 1
107: requires: !single
109: test:
110: args: -l 0 -k 0
111: suffix: 2
112: requires: !single
114: test:
115: args: -extrarow
116: suffix: 3
117: requires: !single
119: TEST*/