Actual source code: ex49.c
slepc-3.21.0 2024-03-30
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));
43: PetscCall(MatCreate(PETSC_COMM_WORLD,&B));
44: PetscCall(MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,N,N));
45: PetscCall(MatSetFromOptions(B));
47: PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
48: for (II=Istart;II<Iend;II++) {
49: i = II/n; j = II-i*n;
50: if (i>0) PetscCall(MatSetValue(A,II,II-n,-0.2,INSERT_VALUES));
51: if (i<m-1) PetscCall(MatSetValue(A,II,II+n,-0.2,INSERT_VALUES));
52: if (j>0) PetscCall(MatSetValue(A,II,II-1,-3.0,INSERT_VALUES));
53: if (j<n-1) PetscCall(MatSetValue(A,II,II+1,-3.0,INSERT_VALUES));
54: PetscCall(MatSetValue(A,II,II,7.0,INSERT_VALUES));
55: PetscCall(MatSetValue(B,II,II,2.0,INSERT_VALUES));
56: }
57: if (Istart==0) {
58: PetscCall(MatSetValue(B,0,0,6.0,INSERT_VALUES));
59: PetscCall(MatSetValue(B,0,1,-1.0,INSERT_VALUES));
60: PetscCall(MatSetValue(B,1,0,-1.0,INSERT_VALUES));
61: PetscCall(MatSetValue(B,1,1,1.0,INSERT_VALUES));
62: }
63: PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
64: PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
65: PetscCall(MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY));
66: PetscCall(MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY));
68: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
69: Compute sparser approximations A0 and B0
70: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
72: PetscCall(MatCreate(PETSC_COMM_WORLD,&A0));
73: PetscCall(MatSetSizes(A0,PETSC_DECIDE,PETSC_DECIDE,N,N));
74: PetscCall(MatSetFromOptions(A0));
76: PetscCall(MatCreate(PETSC_COMM_WORLD,&B0));
77: PetscCall(MatSetSizes(B0,PETSC_DECIDE,PETSC_DECIDE,N,N));
78: PetscCall(MatSetFromOptions(B0));
80: PetscCall(MatGetOwnershipRange(A0,&Istart,&Iend));
81: for (II=Istart;II<Iend;II++) {
82: i = II/n; j = II-i*n;
83: if (j>0) PetscCall(MatSetValue(A0,II,II-1,-3.0,INSERT_VALUES));
84: if (j<n-1) PetscCall(MatSetValue(A0,II,II+1,-3.0,INSERT_VALUES));
85: PetscCall(MatSetValue(A0,II,II,7.0,INSERT_VALUES));
86: PetscCall(MatSetValue(B0,II,II,2.0,INSERT_VALUES));
87: }
88: if (Istart==0) {
89: PetscCall(MatSetValue(B0,0,0,6.0,INSERT_VALUES));
90: PetscCall(MatSetValue(B0,1,1,1.0,INSERT_VALUES));
91: }
92: PetscCall(MatAssemblyBegin(A0,MAT_FINAL_ASSEMBLY));
93: PetscCall(MatAssemblyEnd(A0,MAT_FINAL_ASSEMBLY));
94: PetscCall(MatAssemblyBegin(B0,MAT_FINAL_ASSEMBLY));
95: PetscCall(MatAssemblyEnd(B0,MAT_FINAL_ASSEMBLY));
97: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
98: Create the eigensolver and set various options
99: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
101: PetscCall(EPSCreate(PETSC_COMM_WORLD,&eps));
102: PetscCall(EPSSetOperators(eps,A,B));
103: PetscCall(EPSSetProblemType(eps,EPS_GHEP));
104: PetscCall(EPSGetST(eps,&st));
105: PetscCall(STSetType(st,STSINVERT));
106: mats[0] = A0; mats[1] = B0;
107: PetscCall(STSetSplitPreconditioner(st,2,mats,SUBSET_NONZERO_PATTERN));
108: PetscCall(EPSSetTarget(eps,0.0));
109: PetscCall(EPSSetWhichEigenpairs(eps,EPS_TARGET_MAGNITUDE));
110: PetscCall(EPSSetFromOptions(eps));
112: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
113: Solve the eigensystem and display solution
114: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
116: PetscCall(EPSSolve(eps));
118: /* show detailed info unless -terse option is given by user */
119: PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
120: if (terse) PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL));
121: else {
122: PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
123: PetscCall(EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD));
124: PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD));
125: PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
126: }
127: PetscCall(EPSDestroy(&eps));
128: PetscCall(MatDestroy(&A));
129: PetscCall(MatDestroy(&B));
130: PetscCall(MatDestroy(&A0));
131: PetscCall(MatDestroy(&B0));
132: PetscCall(SlepcFinalize());
133: return 0;
134: }
136: /*TEST
138: testset:
139: args: -eps_nev 4 -terse
140: output_file: output/ex49_1.out
141: requires: !single
142: test:
143: suffix: 1
144: test:
145: suffix: 1_jd
146: args: -eps_type jd -st_type precond
147: test:
148: suffix: 1_lobpcg
149: args: -eps_type lobpcg -st_type precond -eps_smallest_real -st_shift 0.2
151: testset:
152: args: -eps_type ciss -eps_all -rg_type ellipse -rg_ellipse_center 0 -rg_ellipse_radius 0.34 -rg_ellipse_vscale .2 -terse
153: output_file: output/ex49_2.out
154: test:
155: suffix: 2
156: test:
157: suffix: 2_nost
158: args: -eps_ciss_usest 0
159: requires: !single
160: test:
161: suffix: 2_par
162: nsize: 2
163: args: -eps_ciss_partitions 2
164: requires: !single
166: TEST*/