Actual source code: test35.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[] = "Test interface to external package BLOPEX.\n\n"
12: "This is based on ex12.c. 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; /* matrices */
21: EPS eps; /* eigenproblem solver context */
22: ST st; /* spectral transformation context */
23: KSP ksp;
24: PC pc;
25: PetscInt N,n=35,m,Istart,Iend,II,i,j,bs;
26: PetscBool flag;
28: SlepcInitialize(&argc,&argv,(char*)0,help);
30: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
31: PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
32: if (!flag) m=n;
33: N = n*m;
34: PetscPrintf(PETSC_COMM_WORLD,"\nGeneralized eigenproblem with BLOPEX, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m);
36: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
37: Compute the matrices that define the eigensystem, Ax=kBx
38: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
40: MatCreate(PETSC_COMM_WORLD,&A);
41: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);
42: MatSetFromOptions(A);
43: MatSetUp(A);
45: MatCreate(PETSC_COMM_WORLD,&B);
46: MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,N,N);
47: MatSetFromOptions(B);
48: MatSetUp(B);
50: MatGetOwnershipRange(A,&Istart,&Iend);
51: for (II=Istart;II<Iend;II++) {
52: i = II/n; j = II-i*n;
53: if (i>0) MatSetValue(A,II,II-n,-1.0,INSERT_VALUES);
54: if (i<m-1) MatSetValue(A,II,II+n,-1.0,INSERT_VALUES);
55: if (j>0) MatSetValue(A,II,II-1,-1.0,INSERT_VALUES);
56: if (j<n-1) MatSetValue(A,II,II+1,-1.0,INSERT_VALUES);
57: MatSetValue(A,II,II,4.0,INSERT_VALUES);
58: MatSetValue(B,II,II,2.0,INSERT_VALUES);
59: }
60: if (Istart==0) {
61: MatSetValue(B,0,0,6.0,INSERT_VALUES);
62: MatSetValue(B,0,1,-1.0,INSERT_VALUES);
63: MatSetValue(B,1,0,-1.0,INSERT_VALUES);
64: MatSetValue(B,1,1,1.0,INSERT_VALUES);
65: }
67: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
68: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
69: MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
70: MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
72: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
73: Create the eigensolver and set various options
74: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
76: EPSCreate(PETSC_COMM_WORLD,&eps);
77: EPSSetOperators(eps,A,B);
78: EPSSetProblemType(eps,EPS_GHEP);
79: EPSSetType(eps,EPSBLOPEX);
81: /*
82: Set several options
83: */
84: EPSSetWhichEigenpairs(eps,EPS_SMALLEST_REAL);
85: EPSGetST(eps,&st);
86: STSetType(st,STPRECOND);
87: STGetKSP(st,&ksp);
88: KSPGetPC(ksp,&pc);
89: KSPSetType(ksp,KSPPREONLY);
90: PCSetType(pc,PCICC);
92: EPSBLOPEXSetBlockSize(eps,4);
93: EPSSetFromOptions(eps);
95: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
96: Compute all eigenvalues in interval and display info
97: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
99: EPSSolve(eps);
100: EPSBLOPEXGetBlockSize(eps,&bs);
101: PetscPrintf(PETSC_COMM_WORLD," BLOPEX: using block size %" PetscInt_FMT "\n",bs);
103: EPSErrorView(eps,EPS_ERROR_ABSOLUTE,NULL);
105: EPSDestroy(&eps);
106: MatDestroy(&A);
107: MatDestroy(&B);
108: SlepcFinalize();
109: return 0;
110: }
112: /*TEST
114: build:
115: requires: blopex
117: test:
118: suffix: 1
119: args: -eps_nev 8 -eps_view
120: requires: blopex
121: filter: grep -v tolerance | sed -e "s/hermitian/symmetric/"
123: TEST*/