Actual source code: ex49.c
slepc-3.19.0 2023-03-31
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[] = "User-defined split preconditioner when solving a generalized eigenproblem.\n\n"
12: "The command line options are:\n"
13: " -n <n>, where <n> = number of grid subdivisions in x dimension.\n"
14: " -m <m>, where <m> = number of grid subdivisions in y dimension.\n\n";
16: #include <slepceps.h>
18: int main(int argc,char **argv)
19: {
20: Mat A,B,A0,B0,mats[2]; /* problem matrices and sparser approximations */
21: EPS eps; /* eigenproblem solver context */
22: ST st;
23: PetscInt N,n=24,m,Istart,Iend,II,i,j;
24: PetscBool flag,terse;
26: PetscFunctionBeginUser;
27: PetscCall(SlepcInitialize(&argc,&argv,(char*)0,help));
29: PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
30: PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag));
31: if (!flag) m=n;
32: N = n*m;
33: PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nGHEP with split preconditioner, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m));
35: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
36: Compute the problem matrices A and B
37: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
39: PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
40: PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N));
41: PetscCall(MatSetFromOptions(A));
42: PetscCall(MatSetUp(A));
44: PetscCall(MatCreate(PETSC_COMM_WORLD,&B));
45: PetscCall(MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,N,N));
46: PetscCall(MatSetFromOptions(B));
47: PetscCall(MatSetUp(B));
49: PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
50: for (II=Istart;II<Iend;II++) {
51: i = II/n; j = II-i*n;
52: if (i>0) PetscCall(MatSetValue(A,II,II-n,-0.2,INSERT_VALUES));
53: if (i<m-1) PetscCall(MatSetValue(A,II,II+n,-0.2,INSERT_VALUES));
54: if (j>0) PetscCall(MatSetValue(A,II,II-1,-3.0,INSERT_VALUES));
55: if (j<n-1) PetscCall(MatSetValue(A,II,II+1,-3.0,INSERT_VALUES));
56: PetscCall(MatSetValue(A,II,II,7.0,INSERT_VALUES));
57: PetscCall(MatSetValue(B,II,II,2.0,INSERT_VALUES));
58: }
59: if (Istart==0) {
60: PetscCall(MatSetValue(B,0,0,6.0,INSERT_VALUES));
61: PetscCall(MatSetValue(B,0,1,-1.0,INSERT_VALUES));
62: PetscCall(MatSetValue(B,1,0,-1.0,INSERT_VALUES));
63: PetscCall(MatSetValue(B,1,1,1.0,INSERT_VALUES));
64: }
65: PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
66: PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
67: PetscCall(MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY));
68: PetscCall(MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY));
70: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
71: Compute sparser approximations A0 and B0
72: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
74: PetscCall(MatCreate(PETSC_COMM_WORLD,&A0));
75: PetscCall(MatSetSizes(A0,PETSC_DECIDE,PETSC_DECIDE,N,N));
76: PetscCall(MatSetFromOptions(A0));
77: PetscCall(MatSetUp(A0));
79: PetscCall(MatCreate(PETSC_COMM_WORLD,&B0));
80: PetscCall(MatSetSizes(B0,PETSC_DECIDE,PETSC_DECIDE,N,N));
81: PetscCall(MatSetFromOptions(B0));
82: PetscCall(MatSetUp(B0));
84: PetscCall(MatGetOwnershipRange(A0,&Istart,&Iend));
85: for (II=Istart;II<Iend;II++) {
86: i = II/n; j = II-i*n;
87: if (j>0) PetscCall(MatSetValue(A0,II,II-1,-3.0,INSERT_VALUES));
88: if (j<n-1) PetscCall(MatSetValue(A0,II,II+1,-3.0,INSERT_VALUES));
89: PetscCall(MatSetValue(A0,II,II,7.0,INSERT_VALUES));
90: PetscCall(MatSetValue(B0,II,II,2.0,INSERT_VALUES));
91: }
92: if (Istart==0) {
93: PetscCall(MatSetValue(B0,0,0,6.0,INSERT_VALUES));
94: PetscCall(MatSetValue(B0,1,1,1.0,INSERT_VALUES));
95: }
96: PetscCall(MatAssemblyBegin(A0,MAT_FINAL_ASSEMBLY));
97: PetscCall(MatAssemblyEnd(A0,MAT_FINAL_ASSEMBLY));
98: PetscCall(MatAssemblyBegin(B0,MAT_FINAL_ASSEMBLY));
99: PetscCall(MatAssemblyEnd(B0,MAT_FINAL_ASSEMBLY));
101: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
102: Create the eigensolver and set various options
103: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
105: PetscCall(EPSCreate(PETSC_COMM_WORLD,&eps));
106: PetscCall(EPSSetOperators(eps,A,B));
107: PetscCall(EPSSetProblemType(eps,EPS_GHEP));
108: PetscCall(EPSGetST(eps,&st));
109: PetscCall(STSetType(st,STSINVERT));
110: mats[0] = A0; mats[1] = B0;
111: PetscCall(STSetSplitPreconditioner(st,2,mats,SUBSET_NONZERO_PATTERN));
112: PetscCall(EPSSetTarget(eps,0.0));
113: PetscCall(EPSSetWhichEigenpairs(eps,EPS_TARGET_MAGNITUDE));
114: PetscCall(EPSSetFromOptions(eps));
116: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
117: Solve the eigensystem and display solution
118: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
120: PetscCall(EPSSolve(eps));
122: /* show detailed info unless -terse option is given by user */
123: PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
124: if (terse) PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL));
125: else {
126: PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
127: PetscCall(EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD));
128: PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD));
129: PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
130: }
131: PetscCall(EPSDestroy(&eps));
132: PetscCall(MatDestroy(&A));
133: PetscCall(MatDestroy(&B));
134: PetscCall(MatDestroy(&A0));
135: PetscCall(MatDestroy(&B0));
136: PetscCall(SlepcFinalize());
137: return 0;
138: }
140: /*TEST
142: testset:
143: args: -eps_nev 4 -terse
144: output_file: output/ex49_1.out
145: requires: !single
146: test:
147: suffix: 1
148: test:
149: suffix: 1_jd
150: args: -eps_type jd -st_type precond
151: test:
152: suffix: 1_lobpcg
153: args: -eps_type lobpcg -st_type precond -eps_smallest_real -st_shift 0.2
155: testset:
156: args: -eps_type ciss -eps_all -rg_type ellipse -rg_ellipse_center 0 -rg_ellipse_radius 0.34 -rg_ellipse_vscale .2 -terse
157: output_file: output/ex49_2.out
158: test:
159: suffix: 2
160: test:
161: suffix: 2_nost
162: args: -eps_ciss_usest 0
163: requires: !single
164: test:
165: suffix: 2_par
166: nsize: 2
167: args: -eps_ciss_partitions 2
168: requires: !single
170: TEST*/