Line data Source code
1 : /*
2 : - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3 : SLEPc - Scalable Library for Eigenvalue Problem Computations
4 : Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain
5 :
6 : This file is part of SLEPc.
7 : SLEPc is distributed under a 2-clause BSD license (see LICENSE).
8 : - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
9 : */
10 : /*
11 : This example implements one of the problems found at
12 : NLEVP: A Collection of Nonlinear Eigenvalue Problems,
13 : The University of Manchester.
14 : The details of the collection can be found at:
15 : [1] T. Betcke et al., "NLEVP: A Collection of Nonlinear Eigenvalue
16 : Problems", ACM Trans. Math. Software 39(2), Article 7, 2013.
17 :
18 : The spring problem is a QEP from the finite element model of a damped
19 : mass-spring system. This implementation supports only scalar parameters,
20 : that is all masses, dampers and springs have the same constants.
21 : Furthermore, this implementation does not consider different constants
22 : for dampers and springs connecting adjacent masses or masses to the ground.
23 : */
24 :
25 : static char help[] = "FEM model of a damped mass-spring system.\n\n"
26 : "The command line options are:\n"
27 : " -n <n> ... dimension of the matrices.\n"
28 : " -mu <value> ... mass (default 1).\n"
29 : " -tau <value> ... damping constant of the dampers (default 10).\n"
30 : " -kappa <value> ... damping constant of the springs (default 5).\n\n";
31 :
32 : #include <slepcpep.h>
33 :
34 9 : int main(int argc,char **argv)
35 : {
36 9 : Mat M,C,K,A[3]; /* problem matrices */
37 9 : PEP pep; /* polynomial eigenproblem solver context */
38 9 : PetscInt n=5,Istart,Iend,i;
39 9 : PetscReal mu=1.0,tau=10.0,kappa=5.0;
40 9 : PetscBool terse;
41 :
42 9 : PetscFunctionBeginUser;
43 9 : PetscCall(SlepcInitialize(&argc,&argv,(char*)0,help));
44 :
45 9 : PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
46 9 : PetscCall(PetscOptionsGetReal(NULL,NULL,"-mu",&mu,NULL));
47 9 : PetscCall(PetscOptionsGetReal(NULL,NULL,"-tau",&tau,NULL));
48 9 : PetscCall(PetscOptionsGetReal(NULL,NULL,"-kappa",&kappa,NULL));
49 9 : PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nDamped mass-spring system, n=%" PetscInt_FMT " mu=%g tau=%g kappa=%g\n\n",n,(double)mu,(double)tau,(double)kappa));
50 :
51 : /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
52 : Compute the matrices that define the eigensystem, (k^2*M+k*C+K)x=0
53 : - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
54 :
55 : /* K is a tridiagonal */
56 9 : PetscCall(MatCreate(PETSC_COMM_WORLD,&K));
57 9 : PetscCall(MatSetSizes(K,PETSC_DECIDE,PETSC_DECIDE,n,n));
58 9 : PetscCall(MatSetFromOptions(K));
59 :
60 9 : PetscCall(MatGetOwnershipRange(K,&Istart,&Iend));
61 1053 : for (i=Istart;i<Iend;i++) {
62 1044 : if (i>0) PetscCall(MatSetValue(K,i,i-1,-kappa,INSERT_VALUES));
63 1044 : PetscCall(MatSetValue(K,i,i,kappa*3.0,INSERT_VALUES));
64 1044 : if (i<n-1) PetscCall(MatSetValue(K,i,i+1,-kappa,INSERT_VALUES));
65 : }
66 :
67 9 : PetscCall(MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY));
68 9 : PetscCall(MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY));
69 :
70 : /* C is a tridiagonal */
71 9 : PetscCall(MatCreate(PETSC_COMM_WORLD,&C));
72 9 : PetscCall(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,n,n));
73 9 : PetscCall(MatSetFromOptions(C));
74 :
75 9 : PetscCall(MatGetOwnershipRange(C,&Istart,&Iend));
76 1053 : for (i=Istart;i<Iend;i++) {
77 1044 : if (i>0) PetscCall(MatSetValue(C,i,i-1,-tau,INSERT_VALUES));
78 1044 : PetscCall(MatSetValue(C,i,i,tau*3.0,INSERT_VALUES));
79 1044 : if (i<n-1) PetscCall(MatSetValue(C,i,i+1,-tau,INSERT_VALUES));
80 : }
81 :
82 9 : PetscCall(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY));
83 9 : PetscCall(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY));
84 :
85 : /* M is a diagonal matrix */
86 9 : PetscCall(MatCreate(PETSC_COMM_WORLD,&M));
87 9 : PetscCall(MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,n,n));
88 9 : PetscCall(MatSetFromOptions(M));
89 9 : PetscCall(MatGetOwnershipRange(M,&Istart,&Iend));
90 1053 : for (i=Istart;i<Iend;i++) PetscCall(MatSetValue(M,i,i,mu,INSERT_VALUES));
91 9 : PetscCall(MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY));
92 9 : PetscCall(MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY));
93 :
94 : /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
95 : Create the eigensolver and solve the problem
96 : - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
97 :
98 9 : PetscCall(PEPCreate(PETSC_COMM_WORLD,&pep));
99 9 : A[0] = K; A[1] = C; A[2] = M;
100 9 : PetscCall(PEPSetOperators(pep,3,A));
101 9 : PetscCall(PEPSetFromOptions(pep));
102 9 : PetscCall(PEPSolve(pep));
103 :
104 : /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
105 : Display solution and clean up
106 : - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
107 :
108 : /* show detailed info unless -terse option is given by user */
109 9 : PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
110 9 : if (terse) PetscCall(PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL));
111 : else {
112 0 : PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
113 0 : PetscCall(PEPConvergedReasonView(pep,PETSC_VIEWER_STDOUT_WORLD));
114 0 : PetscCall(PEPErrorView(pep,PEP_ERROR_BACKWARD,PETSC_VIEWER_STDOUT_WORLD));
115 0 : PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
116 : }
117 9 : PetscCall(PEPDestroy(&pep));
118 9 : PetscCall(MatDestroy(&M));
119 9 : PetscCall(MatDestroy(&C));
120 9 : PetscCall(MatDestroy(&K));
121 9 : PetscCall(SlepcFinalize());
122 : return 0;
123 : }
124 :
125 : /*TEST
126 :
127 : testset:
128 : args: -pep_nev 4 -n 24 -pep_ncv 18 -pep_target -.5 -st_type sinvert -pep_scale diagonal -terse
129 : output_file: output/spring_1.out
130 : filter: sed -e "s/[+-]0\.0*i//g"
131 : test:
132 : suffix: 1
133 : args: -pep_type {{toar linear}} -pep_conv_norm
134 : test:
135 : suffix: 1_stoar
136 : args: -pep_type stoar -pep_hermitian -pep_conv_rel
137 : test:
138 : suffix: 1_qarnoldi
139 : args: -pep_type qarnoldi -pep_conv_rel
140 : test:
141 : suffix: 1_cuda
142 : args: -mat_type aijcusparse
143 : requires: cuda
144 :
145 : test:
146 : suffix: 2
147 : args: -pep_type jd -pep_jd_minimality_index 1 -pep_nev 4 -n 24 -pep_ncv 18 -pep_target -50 -terse
148 : requires: !single
149 : filter: sed -e "s/[+-]0\.0*i//g"
150 :
151 : test:
152 : suffix: 3
153 : args: -n 300 -pep_hermitian -pep_interval -10.1,-9.5 -pep_type stoar -st_type sinvert -st_pc_type cholesky -terse
154 : filter: sed -e "s/52565/52566/" | sed -e "s/90758/90759/"
155 : requires: !single
156 :
157 : test:
158 : suffix: 4
159 : args: -n 300 -pep_hyperbolic -pep_interval -9.6,-.527 -pep_type stoar -st_type sinvert -st_pc_type cholesky -terse
160 : requires: !single
161 : timeoutfactor: 2
162 :
163 : test:
164 : suffix: 5
165 : args: -n 300 -pep_hyperbolic -pep_interval -.506,-.3 -pep_type stoar -st_type sinvert -st_pc_type cholesky -pep_stoar_nev 11 -terse
166 : requires: !single
167 :
168 : test:
169 : suffix: 6
170 : args: -n 24 -pep_ncv 18 -pep_target -.5 -terse -pep_type jd -pep_jd_restart .6 -pep_jd_fix .001
171 : requires: !single
172 :
173 : TEST*/
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