Actual source code: loaded_string.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: */
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.
18: The loaded_string problem is a rational eigenvalue problem for the
19: finite element model of a loaded vibrating string.
20: */
22: static char help[] = "Finite element model of a loaded vibrating string.\n\n"
23: "The command line options are:\n"
24: " -n <n>, dimension of the matrices.\n"
25: " -kappa <kappa>, stiffness of elastic spring.\n"
26: " -mass <m>, mass of the attached load.\n\n";
28: #include <slepcnep.h>
30: #define NMAT 3
32: int main(int argc,char **argv)
33: {
34: Mat A[NMAT]; /* problem matrices */
35: FN f[NMAT]; /* functions to define the nonlinear operator */
36: NEP nep; /* nonlinear eigensolver context */
37: PetscInt n=100,Istart,Iend,i;
38: PetscReal kappa=1.0,m=1.0;
39: PetscScalar sigma,numer[2],denom[2];
40: PetscBool terse;
43: SlepcInitialize(&argc,&argv,(char*)0,help);
45: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
46: PetscOptionsGetReal(NULL,NULL,"-kappa",&kappa,NULL);
47: PetscOptionsGetReal(NULL,NULL,"-mass",&m,NULL);
48: sigma = kappa/m;
49: PetscPrintf(PETSC_COMM_WORLD,"Loaded vibrating string, n=%" PetscInt_FMT " kappa=%g m=%g\n\n",n,(double)kappa,(double)m);
51: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
52: Build the problem matrices
53: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
55: /* initialize matrices */
56: for (i=0;i<NMAT;i++) {
57: MatCreate(PETSC_COMM_WORLD,&A[i]);
58: MatSetSizes(A[i],PETSC_DECIDE,PETSC_DECIDE,n,n);
59: MatSetFromOptions(A[i]);
60: MatSetUp(A[i]);
61: }
62: MatGetOwnershipRange(A[0],&Istart,&Iend);
64: /* A0 */
65: for (i=Istart;i<Iend;i++) {
66: MatSetValue(A[0],i,i,(i==n-1)?1.0*n:2.0*n,INSERT_VALUES);
67: if (i>0) MatSetValue(A[0],i,i-1,-1.0*n,INSERT_VALUES);
68: if (i<n-1) MatSetValue(A[0],i,i+1,-1.0*n,INSERT_VALUES);
69: }
71: /* A1 */
72: for (i=Istart;i<Iend;i++) {
73: MatSetValue(A[1],i,i,(i==n-1)?2.0/(6.0*n):4.0/(6.0*n),INSERT_VALUES);
74: if (i>0) MatSetValue(A[1],i,i-1,1.0/(6.0*n),INSERT_VALUES);
75: if (i<n-1) MatSetValue(A[1],i,i+1,1.0/(6.0*n),INSERT_VALUES);
76: }
78: /* A2 */
79: if (Istart<=n-1 && n-1<Iend) MatSetValue(A[2],n-1,n-1,kappa,INSERT_VALUES);
81: /* assemble matrices */
82: for (i=0;i<NMAT;i++) MatAssemblyBegin(A[i],MAT_FINAL_ASSEMBLY);
83: for (i=0;i<NMAT;i++) MatAssemblyEnd(A[i],MAT_FINAL_ASSEMBLY);
85: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
86: Create the problem functions
87: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
89: /* f1=1 */
90: FNCreate(PETSC_COMM_WORLD,&f[0]);
91: FNSetType(f[0],FNRATIONAL);
92: numer[0] = 1.0;
93: FNRationalSetNumerator(f[0],1,numer);
95: /* f2=-lambda */
96: FNCreate(PETSC_COMM_WORLD,&f[1]);
97: FNSetType(f[1],FNRATIONAL);
98: numer[0] = -1.0; numer[1] = 0.0;
99: FNRationalSetNumerator(f[1],2,numer);
101: /* f3=lambda/(lambda-sigma) */
102: FNCreate(PETSC_COMM_WORLD,&f[2]);
103: FNSetType(f[2],FNRATIONAL);
104: numer[0] = 1.0; numer[1] = 0.0;
105: denom[0] = 1.0; denom[1] = -sigma;
106: FNRationalSetNumerator(f[2],2,numer);
107: FNRationalSetDenominator(f[2],2,denom);
109: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
110: Create the eigensolver and solve the problem
111: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
113: NEPCreate(PETSC_COMM_WORLD,&nep);
114: NEPSetSplitOperator(nep,3,A,f,SUBSET_NONZERO_PATTERN);
115: NEPSetProblemType(nep,NEP_RATIONAL);
116: NEPSetFromOptions(nep);
117: NEPSolve(nep);
119: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
120: Display solution and clean up
121: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
123: /* show detailed info unless -terse option is given by user */
124: PetscOptionsHasName(NULL,NULL,"-terse",&terse);
125: if (terse) NEPErrorView(nep,NEP_ERROR_RELATIVE,NULL);
126: else {
127: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
128: NEPConvergedReasonView(nep,PETSC_VIEWER_STDOUT_WORLD);
129: NEPErrorView(nep,NEP_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
130: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
131: }
132: NEPDestroy(&nep);
133: for (i=0;i<NMAT;i++) {
134: MatDestroy(&A[i]);
135: FNDestroy(&f[i]);
136: }
137: SlepcFinalize();
138: return 0;
139: }
141: /*TEST
143: test:
144: suffix: 1
145: args: -nep_type rii -nep_target 4 -terse
146: requires: !single
147: filter: sed -e "s/[+-]0\.0*i//g"
149: testset:
150: args: -nep_type interpol -rg_type interval -rg_interval_endpoints 5,700,-.1,.1 -nep_nev 7 -nep_target 5 -nep_interpol_interpolation_degree 12 -nep_refine simple -terse
151: requires: !single
152: output_file: output/loaded_string_2.out
153: test:
154: suffix: 2
155: args: -nep_refine_scheme {{schur explicit}}
156: test:
157: suffix: 2_mbe
158: args: -nep_refine_scheme mbe -nep_refine_ksp_type preonly -nep_refine_pc_type lu
160: testset:
161: nsize: 2
162: args: -nep_type interpol -rg_type interval -rg_interval_endpoints 5,700,-.1,.1 -nep_nev 7 -nep_target 5 -nep_interpol_interpolation_degree 12 -nep_refine simple -nep_refine_partitions 2 -nep_interpol_st_ksp_type bcgs -nep_interpol_st_pc_type bjacobi -terse
163: requires: !single
164: output_file: output/loaded_string_2.out
165: timeoutfactor: 2
166: test:
167: suffix: 3_explicit
168: args: -nep_refine_scheme explicit
169: test:
170: suffix: 3_mbe
171: args: -nep_refine_scheme mbe -nep_refine_ksp_type preonly -nep_refine_pc_type cholesky
173: test:
174: suffix: 4
175: nsize: 4
176: args: -nep_type interpol -rg_type interval -rg_interval_endpoints 5,700,-.1,.1 -nep_nev 7 -nep_target 5 -nep_interpol_interpolation_degree 10 -nep_refine simple -nep_refine_partitions 2 -nep_refine_scheme explicit -nep_interpol_st_ksp_type bcgs -nep_interpol_st_pc_type bjacobi -terse -log_exclude nep,pep,fn
177: requires: !single
178: output_file: output/loaded_string_2.out
179: timeoutfactor: 4
181: test:
182: suffix: 5
183: args: -nep_type nleigs -rg_type interval -rg_interval_endpoints 4,700,-.1,.1 -nep_nev 8 -nep_target 5 -terse
184: filter: sed -e "s/[+-]0\.0*i//g"
185: requires: !single
187: test:
188: suffix: 6
189: args: -nep_type nleigs -rg_type interval -rg_interval_endpoints 100,700 -nep_nev 5 -nep_tol 1e-9 -nep_target 140 -nep_nleigs_interpolation_degree 15 -nep_general -terse
190: requires: !complex !single
192: test:
193: suffix: 6_complex
194: args: -nep_type nleigs -rg_type interval -rg_interval_endpoints 100,700,-.1,.1 -nep_nev 5 -nep_tol 1e-9 -nep_target 140 -nep_nleigs_interpolation_degree 15 -nep_general -terse
195: filter: sed -e "s/[+-]0\.0*i//g"
196: requires: complex !single
197: output_file: output/loaded_string_6.out
199: test:
200: suffix: 7
201: args: -nep_type interpol -rg_type interval -rg_interval_endpoints 5,700 -nep_nev 5 -nep_target 100 -nep_interpol_interpolation_degree 20 -nep_ncv 20 -n 20 -nep_refine simple -nep_refine_its 1 -terse
202: requires: !complex double
204: test:
205: suffix: 7_complex
206: args: -nep_type interpol -rg_type interval -rg_interval_endpoints 5,700,-.1,.1 -nep_nev 5 -nep_target 100 -nep_interpol_interpolation_degree 20 -nep_ncv 20 -n 20 -nep_refine simple -nep_refine_its 1 -terse
207: requires: complex double
208: output_file: output/loaded_string_7.out
210: testset:
211: args: -nep_target 10 -nep_nev 3 -nep_tol 5e-10 -terse
212: requires: !single
213: output_file: output/loaded_string_8.out
214: filter: sed -e "s/[+-]0\.0*i//g"
215: test:
216: suffix: 8
217: args: -nep_type {{rii slp narnoldi}}
218: test:
219: suffix: 8_rii_thres
220: args: -nep_type rii -nep_rii_deflation_threshold 5e-10
221: test:
222: suffix: 8_slp_thres
223: args: -nep_type slp -nep_slp_deflation_threshold 5e-10
225: test:
226: suffix: 8_slp_two_thres
227: args: -nep_type slp -nep_slp_deflation_threshold 5e-10 -nep_two_sided
229: test:
230: suffix: 9
231: args: -nep_type ciss -rg_type ellipse -rg_ellipse_center 500 -rg_ellipse_radius 500 -rg_ellipse_vscale .1 -nep_ciss_moments 4 -nep_ciss_blocksize 5 -terse
232: requires: complex double
234: TEST*/