Actual source code: test17.c
slepc-3.17.0 2022-03-31
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 DSPEP with complex eigenvalues.\n\n";
13: #include <slepcds.h>
15: int main(int argc,char **argv)
16: {
17: DS ds;
18: SlepcSC sc;
19: Mat X;
20: Vec x0;
21: PetscScalar *K,*M,*wr,*wi;
22: PetscReal re,im,nrm;
23: PetscInt i,n=10,d=2,ld;
24: PetscViewer viewer;
25: PetscBool verbose;
27: SlepcInitialize(&argc,&argv,(char*)0,help);
28: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
29: PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type PEP - n=%" PetscInt_FMT ".\n",n);
30: PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
32: /* Create DS object */
33: DSCreate(PETSC_COMM_WORLD,&ds);
34: DSSetType(ds,DSPEP);
35: DSSetFromOptions(ds);
36: DSPEPSetDegree(ds,d);
38: /* Set dimensions */
39: ld = n+2; /* test leading dimension larger than 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 matrices */
51: DSGetArray(ds,DS_MAT_E0,&K);
52: for (i=0;i<n;i++) K[i+i*ld] = 2.0;
53: for (i=1;i<n;i++) {
54: K[i+(i-1)*ld] = -1.0;
55: K[(i-1)+i*ld] = -1.0;
56: }
57: DSRestoreArray(ds,DS_MAT_E0,&K);
58: DSGetArray(ds,DS_MAT_E2,&M);
59: for (i=0;i<n;i++) M[i+i*ld] = 1.0;
60: DSRestoreArray(ds,DS_MAT_E2,&M);
62: if (verbose) {
63: PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
64: DSView(ds,viewer);
65: }
67: /* Solve */
68: PetscMalloc2(d*n,&wr,d*n,&wi);
69: DSGetSlepcSC(ds,&sc);
70: sc->comparison = SlepcCompareLargestImaginary;
71: sc->comparisonctx = NULL;
72: sc->map = NULL;
73: sc->mapobj = NULL;
74: DSSolve(ds,wr,wi);
75: DSSort(ds,wr,wi,NULL,NULL,NULL);
76: if (verbose) {
77: PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
78: DSView(ds,viewer);
79: }
81: /* Print eigenvalues */
82: PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
83: for (i=0;i<d*n;i++) {
84: #if defined(PETSC_USE_COMPLEX)
85: re = PetscRealPart(wr[i]);
86: im = PetscImaginaryPart(wr[i]);
87: #else
88: re = wr[i];
89: im = wi[i];
90: #endif
91: if (PetscAbs(im)<1e-10) PetscViewerASCIIPrintf(viewer," %.5f\n",(double)re);
92: else PetscViewerASCIIPrintf(viewer," %.5f%+.5fi\n",(double)re,(double)im);
93: }
95: /* Eigenvectors */
96: DSVectors(ds,DS_MAT_X,NULL,NULL); /* all eigenvectors */
97: DSGetMat(ds,DS_MAT_X,&X);
98: MatCreateVecs(X,NULL,&x0);
99: MatGetColumnVector(X,x0,1);
100: VecNorm(x0,NORM_2,&nrm);
101: MatDestroy(&X);
102: VecDestroy(&x0);
103: PetscPrintf(PETSC_COMM_WORLD,"Norm of 2nd column of X = %.3f\n",(double)nrm);
104: if (verbose) {
105: PetscPrintf(PETSC_COMM_WORLD,"After vectors - - - - - - - - -\n");
106: DSView(ds,viewer);
107: }
109: PetscFree2(wr,wi);
110: DSDestroy(&ds);
111: SlepcFinalize();
112: return 0;
113: }
115: /*TEST
117: test:
118: suffix: 1
119: args: -n 7
120: requires: !complex
122: test:
123: suffix: 1_complex
124: args: -n 7
125: requires: complex
126: filter: sed -e 's/-0.00000/0.00000/'
128: TEST*/