Actual source code: test6.c
slepc-3.21.1 2024-04-26
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: */
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: PetscFunctionBeginUser;
42: PetscCall(SlepcInitialize(&argc,&argv,(char*)0,help));
44: PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
45: PetscCall(PetscOptionsGetReal(NULL,NULL,"-mu",&mu,NULL));
46: PetscCall(PetscOptionsGetReal(NULL,NULL,"-tau",&tau,NULL));
47: PetscCall(PetscOptionsGetReal(NULL,NULL,"-kappa",&kappa,NULL));
49: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
50: Compute the matrices that define the eigensystem, (k^2*M+k*C+K)x=0
51: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
53: /* K is a tridiagonal */
54: PetscCall(MatCreate(PETSC_COMM_WORLD,&K));
55: PetscCall(MatSetSizes(K,PETSC_DECIDE,PETSC_DECIDE,n,n));
56: PetscCall(MatSetFromOptions(K));
58: PetscCall(MatGetOwnershipRange(K,&Istart,&Iend));
59: for (i=Istart;i<Iend;i++) {
60: if (i>0) PetscCall(MatSetValue(K,i,i-1,-kappa,INSERT_VALUES));
61: PetscCall(MatSetValue(K,i,i,kappa*3.0,INSERT_VALUES));
62: if (i<n-1) PetscCall(MatSetValue(K,i,i+1,-kappa,INSERT_VALUES));
63: }
65: PetscCall(MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY));
66: PetscCall(MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY));
68: /* C is a tridiagonal */
69: PetscCall(MatCreate(PETSC_COMM_WORLD,&C));
70: PetscCall(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,n,n));
71: PetscCall(MatSetFromOptions(C));
73: PetscCall(MatGetOwnershipRange(C,&Istart,&Iend));
74: for (i=Istart;i<Iend;i++) {
75: if (i>0) PetscCall(MatSetValue(C,i,i-1,-tau,INSERT_VALUES));
76: PetscCall(MatSetValue(C,i,i,tau*3.0,INSERT_VALUES));
77: if (i<n-1) PetscCall(MatSetValue(C,i,i+1,-tau,INSERT_VALUES));
78: }
80: PetscCall(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY));
81: PetscCall(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY));
83: /* M is a diagonal matrix */
84: PetscCall(MatCreate(PETSC_COMM_WORLD,&M));
85: PetscCall(MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,n,n));
86: PetscCall(MatSetFromOptions(M));
87: PetscCall(MatGetOwnershipRange(M,&Istart,&Iend));
88: for (i=Istart;i<Iend;i++) PetscCall(MatSetValue(M,i,i,mu,INSERT_VALUES));
89: PetscCall(MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY));
90: PetscCall(MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY));
92: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
93: Create the eigensolver and set various options
94: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
96: PetscCall(PEPCreate(PETSC_COMM_WORLD,&pep));
97: A[0] = K; A[1] = C; A[2] = M;
98: PetscCall(PEPSetOperators(pep,3,A));
99: PetscCall(PEPSetProblemType(pep,PEP_GENERAL));
100: PetscCall(PEPSetTolerances(pep,PETSC_SMALL,PETSC_DEFAULT));
101: PetscCall(PEPSetFromOptions(pep));
103: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
104: Solve the eigensystem
105: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
107: PetscCall(PEPSolve(pep));
108: PetscCall(PEPGetDimensions(pep,&nev,NULL,NULL));
109: PetscCall(PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev));
111: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
112: Display solution of first solve
113: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
114: PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
115: if (terse) PetscCall(PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL));
116: else {
117: PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
118: PetscCall(PEPConvergedReasonView(pep,PETSC_VIEWER_STDOUT_WORLD));
119: PetscCall(PEPErrorView(pep,PEP_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD));
120: PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
121: }
122: PetscCall(MatDestroy(&M));
123: PetscCall(MatDestroy(&C));
124: PetscCall(MatDestroy(&K));
126: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
127: Compute the eigensystem, (k^2*M+k*C+K)x=0 for bigger n
128: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
130: n *= 2;
131: /* K is a tridiagonal */
132: PetscCall(MatCreate(PETSC_COMM_WORLD,&K));
133: PetscCall(MatSetSizes(K,PETSC_DECIDE,PETSC_DECIDE,n,n));
134: PetscCall(MatSetFromOptions(K));
136: PetscCall(MatGetOwnershipRange(K,&Istart,&Iend));
137: for (i=Istart;i<Iend;i++) {
138: if (i>0) PetscCall(MatSetValue(K,i,i-1,-kappa,INSERT_VALUES));
139: PetscCall(MatSetValue(K,i,i,kappa*3.0,INSERT_VALUES));
140: if (i<n-1) PetscCall(MatSetValue(K,i,i+1,-kappa,INSERT_VALUES));
141: }
143: PetscCall(MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY));
144: PetscCall(MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY));
146: /* C is a tridiagonal */
147: PetscCall(MatCreate(PETSC_COMM_WORLD,&C));
148: PetscCall(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,n,n));
149: PetscCall(MatSetFromOptions(C));
151: PetscCall(MatGetOwnershipRange(C,&Istart,&Iend));
152: for (i=Istart;i<Iend;i++) {
153: if (i>0) PetscCall(MatSetValue(C,i,i-1,-tau,INSERT_VALUES));
154: PetscCall(MatSetValue(C,i,i,tau*3.0,INSERT_VALUES));
155: if (i<n-1) PetscCall(MatSetValue(C,i,i+1,-tau,INSERT_VALUES));
156: }
158: PetscCall(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY));
159: PetscCall(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY));
161: /* M is a diagonal matrix */
162: PetscCall(MatCreate(PETSC_COMM_WORLD,&M));
163: PetscCall(MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,n,n));
164: PetscCall(MatSetFromOptions(M));
165: PetscCall(MatGetOwnershipRange(M,&Istart,&Iend));
166: for (i=Istart;i<Iend;i++) PetscCall(MatSetValue(M,i,i,mu,INSERT_VALUES));
167: PetscCall(MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY));
168: PetscCall(MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY));
170: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
171: Solve again, calling PEPReset() since matrix size has changed
172: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
173: /* PetscCall(PEPReset(pep)); */ /* not required, will be called in PEPSetOperators() */
174: A[0] = K; A[1] = C; A[2] = M;
175: PetscCall(PEPSetOperators(pep,3,A));
176: PetscCall(PEPSolve(pep));
178: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
179: Display solution and clean up
180: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
181: if (terse) PetscCall(PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL));
182: else {
183: PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
184: PetscCall(PEPConvergedReasonView(pep,PETSC_VIEWER_STDOUT_WORLD));
185: PetscCall(PEPErrorView(pep,PEP_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD));
186: PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
187: }
188: PetscCall(PEPDestroy(&pep));
189: PetscCall(MatDestroy(&M));
190: PetscCall(MatDestroy(&C));
191: PetscCall(MatDestroy(&K));
192: PetscCall(SlepcFinalize());
193: return 0;
194: }
196: /*TEST
198: test:
199: suffix: 1
200: args: -pep_type {{toar qarnoldi linear}} -pep_nev 4 -terse
201: requires: double
203: test:
204: suffix: 2
205: args: -pep_type stoar -pep_hermitian -pep_nev 4 -terse
206: requires: !single
208: TEST*/