Actual source code: test6.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: */
10: /*
11: Example based on spring problem in NLEVP collection [1]. See the parameters
12: meaning at Example 2 in [2].
14: [1] T. Betcke, N. J. Higham, V. Mehrmann, C. Schroder, and F. Tisseur,
15: NLEVP: A Collection of Nonlinear Eigenvalue Problems, MIMS EPrint
16: 2010.98, November 2010.
17: [2] F. Tisseur, Backward error and condition of polynomial eigenvalue
18: problems, Linear Algebra and its Applications, 309 (2000), pp. 339--361,
19: April 2000.
20: */
22: static char help[] = "Tests multiple calls to PEPSolve with different matrix of different size.\n\n"
23: "This is based on the spring problem from NLEVP collection.\n\n"
24: "The command line options are:\n"
25: " -n <n> ... number of grid subdivisions.\n"
26: " -mu <value> ... mass (default 1).\n"
27: " -tau <value> ... damping constant of the dampers (default 10).\n"
28: " -kappa <value> ... damping constant of the springs (default 5).\n"
29: " -initv ... set an initial vector.\n\n";
31: #include <slepcpep.h>
33: int main(int argc,char **argv)
34: {
35: Mat M,C,K,A[3]; /* problem matrices */
36: PEP pep; /* polynomial eigenproblem solver context */
37: PetscInt n=30,Istart,Iend,i,nev;
38: PetscReal mu=1.0,tau=10.0,kappa=5.0;
39: PetscBool terse=PETSC_FALSE;
41: SlepcInitialize(&argc,&argv,(char*)0,help);
43: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
44: PetscOptionsGetReal(NULL,NULL,"-mu",&mu,NULL);
45: PetscOptionsGetReal(NULL,NULL,"-tau",&tau,NULL);
46: PetscOptionsGetReal(NULL,NULL,"-kappa",&kappa,NULL);
48: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
49: Compute the matrices that define the eigensystem, (k^2*M+k*C+K)x=0
50: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
52: /* K is a tridiagonal */
53: MatCreate(PETSC_COMM_WORLD,&K);
54: MatSetSizes(K,PETSC_DECIDE,PETSC_DECIDE,n,n);
55: MatSetFromOptions(K);
56: MatSetUp(K);
58: MatGetOwnershipRange(K,&Istart,&Iend);
59: for (i=Istart;i<Iend;i++) {
60: if (i>0) MatSetValue(K,i,i-1,-kappa,INSERT_VALUES);
61: MatSetValue(K,i,i,kappa*3.0,INSERT_VALUES);
62: if (i<n-1) MatSetValue(K,i,i+1,-kappa,INSERT_VALUES);
63: }
65: MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY);
66: MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY);
68: /* C is a tridiagonal */
69: MatCreate(PETSC_COMM_WORLD,&C);
70: MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,n,n);
71: MatSetFromOptions(C);
72: MatSetUp(C);
74: MatGetOwnershipRange(C,&Istart,&Iend);
75: for (i=Istart;i<Iend;i++) {
76: if (i>0) MatSetValue(C,i,i-1,-tau,INSERT_VALUES);
77: MatSetValue(C,i,i,tau*3.0,INSERT_VALUES);
78: if (i<n-1) MatSetValue(C,i,i+1,-tau,INSERT_VALUES);
79: }
81: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
82: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
84: /* M is a diagonal matrix */
85: MatCreate(PETSC_COMM_WORLD,&M);
86: MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,n,n);
87: MatSetFromOptions(M);
88: MatSetUp(M);
89: MatGetOwnershipRange(M,&Istart,&Iend);
90: for (i=Istart;i<Iend;i++) MatSetValue(M,i,i,mu,INSERT_VALUES);
91: MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);
92: MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);
94: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
95: Create the eigensolver and set various options
96: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
98: PEPCreate(PETSC_COMM_WORLD,&pep);
99: A[0] = K; A[1] = C; A[2] = M;
100: PEPSetOperators(pep,3,A);
101: PEPSetProblemType(pep,PEP_GENERAL);
102: PEPSetTolerances(pep,PETSC_SMALL,PETSC_DEFAULT);
103: PEPSetFromOptions(pep);
105: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
106: Solve the eigensystem
107: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
109: PEPSolve(pep);
110: PEPGetDimensions(pep,&nev,NULL,NULL);
111: PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev);
113: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
114: Display solution of first solve
115: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
116: PetscOptionsHasName(NULL,NULL,"-terse",&terse);
117: if (terse) PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL);
118: else {
119: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
120: PEPConvergedReasonView(pep,PETSC_VIEWER_STDOUT_WORLD);
121: PEPErrorView(pep,PEP_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
122: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
123: }
124: MatDestroy(&M);
125: MatDestroy(&C);
126: MatDestroy(&K);
128: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
129: Compute the eigensystem, (k^2*M+k*C+K)x=0 for bigger n
130: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
132: n *= 2;
133: /* K is a tridiagonal */
134: MatCreate(PETSC_COMM_WORLD,&K);
135: MatSetSizes(K,PETSC_DECIDE,PETSC_DECIDE,n,n);
136: MatSetFromOptions(K);
137: MatSetUp(K);
139: MatGetOwnershipRange(K,&Istart,&Iend);
140: for (i=Istart;i<Iend;i++) {
141: if (i>0) MatSetValue(K,i,i-1,-kappa,INSERT_VALUES);
142: MatSetValue(K,i,i,kappa*3.0,INSERT_VALUES);
143: if (i<n-1) MatSetValue(K,i,i+1,-kappa,INSERT_VALUES);
144: }
146: MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY);
147: MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY);
149: /* C is a tridiagonal */
150: MatCreate(PETSC_COMM_WORLD,&C);
151: MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,n,n);
152: MatSetFromOptions(C);
153: MatSetUp(C);
155: MatGetOwnershipRange(C,&Istart,&Iend);
156: for (i=Istart;i<Iend;i++) {
157: if (i>0) MatSetValue(C,i,i-1,-tau,INSERT_VALUES);
158: MatSetValue(C,i,i,tau*3.0,INSERT_VALUES);
159: if (i<n-1) MatSetValue(C,i,i+1,-tau,INSERT_VALUES);
160: }
162: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
163: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
165: /* M is a diagonal matrix */
166: MatCreate(PETSC_COMM_WORLD,&M);
167: MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,n,n);
168: MatSetFromOptions(M);
169: MatSetUp(M);
170: MatGetOwnershipRange(M,&Istart,&Iend);
171: for (i=Istart;i<Iend;i++) MatSetValue(M,i,i,mu,INSERT_VALUES);
172: MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);
173: MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);
175: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
176: Solve again, calling PEPReset() since matrix size has changed
177: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
178: /*PEPReset(pep);*/ /* not required, will be called in PEPSetOperators() */
179: A[0] = K; A[1] = C; A[2] = M;
180: PEPSetOperators(pep,3,A);
181: PEPSolve(pep);
183: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
184: Display solution and clean up
185: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
186: if (terse) PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL);
187: else {
188: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
189: PEPConvergedReasonView(pep,PETSC_VIEWER_STDOUT_WORLD);
190: PEPErrorView(pep,PEP_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
191: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
192: }
193: PEPDestroy(&pep);
194: MatDestroy(&M);
195: MatDestroy(&C);
196: MatDestroy(&K);
197: SlepcFinalize();
198: return 0;
199: }
201: /*TEST
203: test:
204: suffix: 1
205: args: -pep_type {{toar qarnoldi linear}} -pep_nev 4 -terse
206: requires: !single
208: test:
209: suffix: 2
210: args: -pep_type stoar -pep_hermitian -pep_nev 4 -terse
211: requires: !single
213: TEST*/