Actual source code: ex43.c
slepc-3.20.1 2023-11-27
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 eigenproblem, illustrates setting MUMPS options.\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\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\n";
19: #include <slepceps.h>
21: int main(int argc,char **argv)
22: {
23: Mat A,B;
24: #if defined(PETSC_HAVE_MUMPS)
25: Mat K;
26: #endif
27: EPS eps;
28: EPSType type;
29: ST st;
30: KSP ksp;
31: PC pc;
32: PetscInt N,n=10,m=12,Istart,Iend,II,nev,i,j;
33: PetscBool flag,terse;
35: PetscFunctionBeginUser;
36: PetscCall(SlepcInitialize(&argc,&argv,(char*)0,help));
38: PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
39: PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag));
40: N = n*m;
41: PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nGeneralized Eigenproblem, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m));
43: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
44: Compute the matrices that define the eigensystem, Ax=kBx
45: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
47: PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
48: PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N));
49: PetscCall(MatSetFromOptions(A));
50: PetscCall(MatSetUp(A));
52: PetscCall(MatCreate(PETSC_COMM_WORLD,&B));
53: PetscCall(MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,N,N));
54: PetscCall(MatSetFromOptions(B));
55: PetscCall(MatSetUp(B));
57: PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
58: for (II=Istart;II<Iend;II++) {
59: i = II/n; j = II-i*n;
60: if (i>0) PetscCall(MatSetValue(A,II,II-n,-1.0,INSERT_VALUES));
61: if (i<m-1) PetscCall(MatSetValue(A,II,II+n,-1.0,INSERT_VALUES));
62: if (j>0) PetscCall(MatSetValue(A,II,II-1,-1.0,INSERT_VALUES));
63: if (j<n-1) PetscCall(MatSetValue(A,II,II+1,-1.0,INSERT_VALUES));
64: PetscCall(MatSetValue(A,II,II,4.0,INSERT_VALUES));
65: PetscCall(MatSetValue(B,II,II,4.0,INSERT_VALUES));
66: }
68: PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
69: PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
70: PetscCall(MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY));
71: PetscCall(MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY));
73: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
74: Create the eigensolver and set various options
75: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
77: /*
78: Create eigensolver context
79: */
80: PetscCall(EPSCreate(PETSC_COMM_WORLD,&eps));
82: /*
83: Set operators. In this case, it is a generalized eigenvalue problem
84: */
85: PetscCall(EPSSetOperators(eps,A,B));
86: PetscCall(EPSSetProblemType(eps,EPS_GNHEP));
88: /*
89: Set some solver options
90: */
91: PetscCall(EPSSetTarget(eps,1.3));
92: PetscCall(EPSSetDimensions(eps,2,PETSC_DEFAULT,PETSC_DEFAULT));
93: PetscCall(EPSGetST(eps,&st));
94: PetscCall(STSetType(st,STSINVERT));
96: PetscCall(STGetKSP(st,&ksp));
97: PetscCall(KSPSetType(ksp,KSPPREONLY));
98: PetscCall(KSPGetPC(ksp,&pc));
99: PetscCall(PCSetType(pc,PCLU));
101: /*
102: Set MUMPS options if available
103: */
104: #if defined(PETSC_HAVE_MUMPS)
105: PetscCall(PCFactorSetMatSolverType(pc,MATSOLVERMUMPS));
106: /* the next line is required to force the creation of the ST operator and its passing to KSP */
107: PetscCall(STGetOperator(st,NULL));
108: PetscCall(PCFactorSetUpMatSolverType(pc));
109: PetscCall(PCFactorGetMatrix(pc,&K));
110: PetscCall(MatMumpsSetIcntl(K,14,50));
111: PetscCall(MatMumpsSetCntl(K,3,1e-12));
112: #endif
114: /*
115: Let the user change settings at runtime
116: */
117: PetscCall(EPSSetFromOptions(eps));
119: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
120: Solve the eigensystem
121: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
123: PetscCall(EPSSolve(eps));
125: /*
126: Optional: Get some information from the solver and display it
127: */
128: PetscCall(EPSGetType(eps,&type));
129: PetscCall(PetscPrintf(PETSC_COMM_WORLD," Solution method: %s\n\n",type));
130: PetscCall(EPSGetDimensions(eps,&nev,NULL,NULL));
131: PetscCall(PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev));
133: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
134: Display solution and clean up
135: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
137: /* show detailed info unless -terse option is given by user */
138: PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
139: if (terse) PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL));
140: else {
141: PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
142: PetscCall(EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD));
143: PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD));
144: PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
145: }
146: PetscCall(EPSDestroy(&eps));
147: PetscCall(MatDestroy(&A));
148: PetscCall(MatDestroy(&B));
149: PetscCall(SlepcFinalize());
150: return 0;
151: }
153: /*TEST
155: testset:
156: args: -terse
157: output_file: output/ex43_1.out
158: test:
159: suffix: 1
160: test:
161: suffix: 2
162: nsize: 2
163: args: -st_pc_factor_mat_solver_type mumps
164: requires: mumps
166: TEST*/