Actual source code: ex13.c
slepc-3.17.2 2022-08-09
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[] = "Generalized Symmetric eigenproblem.\n\n"
12: "The problem is Ax = lambda Bx, with:\n"
13: " A = Laplacian operator in 2-D\n"
14: " B = diagonal matrix with all values equal to 4 except nulldim zeros\n\n"
15: "The command line options are:\n"
16: " -n <n>, where <n> = number of grid subdivisions in x dimension.\n"
17: " -m <m>, where <m> = number of grid subdivisions in y dimension.\n"
18: " -nulldim <k>, where <k> = dimension of the nullspace of B.\n\n";
20: #include <slepceps.h>
22: int main(int argc,char **argv)
23: {
24: Mat A,B; /* matrices */
25: EPS eps; /* eigenproblem solver context */
26: EPSType type;
27: PetscInt N,n=10,m,Istart,Iend,II,nev,i,j,nulldim=0;
28: PetscBool flag,terse;
30: SlepcInitialize(&argc,&argv,(char*)0,help);
32: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
33: PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
34: if (!flag) m=n;
35: N = n*m;
36: PetscOptionsGetInt(NULL,NULL,"-nulldim",&nulldim,NULL);
37: PetscPrintf(PETSC_COMM_WORLD,"\nGeneralized Symmetric Eigenproblem, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid), null(B)=%" PetscInt_FMT "\n\n",N,n,m,nulldim);
39: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
40: Compute the matrices that define the eigensystem, Ax=kBx
41: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
43: MatCreate(PETSC_COMM_WORLD,&A);
44: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);
45: MatSetFromOptions(A);
46: MatSetUp(A);
48: MatCreate(PETSC_COMM_WORLD,&B);
49: MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,N,N);
50: MatSetFromOptions(B);
51: MatSetUp(B);
53: MatGetOwnershipRange(A,&Istart,&Iend);
54: for (II=Istart;II<Iend;II++) {
55: i = II/n; j = II-i*n;
56: if (i>0) MatSetValue(A,II,II-n,-1.0,INSERT_VALUES);
57: if (i<m-1) MatSetValue(A,II,II+n,-1.0,INSERT_VALUES);
58: if (j>0) MatSetValue(A,II,II-1,-1.0,INSERT_VALUES);
59: if (j<n-1) MatSetValue(A,II,II+1,-1.0,INSERT_VALUES);
60: MatSetValue(A,II,II,4.0,INSERT_VALUES);
61: if (II>=nulldim) MatSetValue(B,II,II,4.0,INSERT_VALUES);
62: }
64: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
65: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
66: MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
67: MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
69: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
70: Create the eigensolver and set various options
71: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
73: /*
74: Create eigensolver context
75: */
76: EPSCreate(PETSC_COMM_WORLD,&eps);
78: /*
79: Set operators. In this case, it is a generalized eigenvalue problem
80: */
81: EPSSetOperators(eps,A,B);
82: EPSSetProblemType(eps,EPS_GHEP);
84: /*
85: Set solver parameters at runtime
86: */
87: EPSSetFromOptions(eps);
89: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
90: Solve the eigensystem
91: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
93: EPSSolve(eps);
95: /*
96: Optional: Get some information from the solver and display it
97: */
98: EPSGetType(eps,&type);
99: PetscPrintf(PETSC_COMM_WORLD," Solution method: %s\n\n",type);
100: EPSGetDimensions(eps,&nev,NULL,NULL);
101: PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev);
103: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
104: Display solution and clean up
105: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
107: /* show detailed info unless -terse option is given by user */
108: PetscOptionsHasName(NULL,NULL,"-terse",&terse);
109: if (terse) EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);
110: else {
111: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
112: EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD);
113: EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
114: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
115: }
116: EPSDestroy(&eps);
117: MatDestroy(&A);
118: MatDestroy(&B);
119: SlepcFinalize();
120: return 0;
121: }
123: /*TEST
125: test:
126: suffix: 1
127: args: -eps_nev 4 -eps_ncv 22 -eps_tol 1e-5 -st_type sinvert -terse
128: filter: grep -v Solution
130: test:
131: suffix: 2
132: args: -n 110 -nulldim 6 -eps_nev 4 -eps_ncv 18 -eps_tol 1e-5 -eps_purify 1 -st_type sinvert -st_matstructure {{different subset}} -terse
133: requires: !single
135: test:
136: suffix: 3
137: args: -eps_nev 3 -eps_tol 1e-5 -mat_type sbaij -st_type sinvert -terse
139: test:
140: suffix: 4
141: args: -eps_nev 4 -eps_tol 1e-4 -eps_smallest_real -eps_type {{gd lobpcg rqcg}} -terse
142: output_file: output/ex13_1.out
143: filter: grep -v Solution
145: test:
146: suffix: 5_primme
147: args: -n 10 -m 12 -eps_nev 4 -eps_target 0.9 -eps_max_it 15000 -eps_type primme -st_pc_type jacobi -terse
148: requires: primme defined(SLEPC_HAVE_PRIMME3) !single
150: test:
151: suffix: 6
152: nsize: 2
153: args: -eps_type ciss -rg_type ellipse -rg_ellipse_center 1.4 -rg_ellipse_radius 0.1 -eps_ciss_partitions 2 -terse
154: requires: !single
156: TEST*/