Actual source code: test6.c
slepc-3.17.1 2022-04-11
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[] = "Diagonal eigenproblem.\n\n"
12: "The command line options are:\n"
13: " -n <n>, where <n> = matrix dimension.\n"
14: " -seed <s>, where <s> = seed for random number generation.\n\n";
16: #include <slepceps.h>
18: int main(int argc,char **argv)
19: {
20: Mat A; /* problem matrix */
21: EPS eps; /* eigenproblem solver context */
22: Vec v0; /* initial vector */
23: PetscRandom rand;
24: PetscReal tol=PETSC_SMALL;
25: PetscInt n=30,i,Istart,Iend,seed=0x12345678;
27: SlepcInitialize(&argc,&argv,(char*)0,help);
29: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
30: PetscPrintf(PETSC_COMM_WORLD,"\nDiagonal Eigenproblem, n=%" PetscInt_FMT "\n\n",n);
32: MatCreate(PETSC_COMM_WORLD,&A);
33: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
34: MatSetFromOptions(A);
35: MatSetUp(A);
36: MatGetOwnershipRange(A,&Istart,&Iend);
37: for (i=Istart;i<Iend;i++) MatSetValue(A,i,i,i+1,INSERT_VALUES);
38: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
39: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
41: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
42: Solve the eigensystem
43: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
44: EPSCreate(PETSC_COMM_WORLD,&eps);
45: EPSSetOperators(eps,A,NULL);
46: EPSSetProblemType(eps,EPS_HEP);
47: EPSSetTolerances(eps,tol,PETSC_DEFAULT);
48: EPSSetFromOptions(eps);
49: /* set random initial vector */
50: MatCreateVecs(A,&v0,NULL);
51: PetscRandomCreate(PETSC_COMM_WORLD,&rand);
52: PetscRandomSetFromOptions(rand);
53: PetscOptionsGetInt(NULL,NULL,"-seed",&seed,NULL);
54: PetscRandomSetSeed(rand,seed);
55: PetscRandomSeed(rand);
56: VecSetRandom(v0,rand);
57: EPSSetInitialSpace(eps,1,&v0);
58: /* call the solver */
59: EPSSolve(eps);
61: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
62: Display solution and clean up
63: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
64: EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);
65: EPSDestroy(&eps);
66: MatDestroy(&A);
67: VecDestroy(&v0);
68: PetscRandomDestroy(&rand);
69: SlepcFinalize();
70: return 0;
71: }
73: /*TEST
75: testset:
76: args: -eps_nev 4
77: requires: !single
78: output_file: output/test6_1.out
79: test:
80: suffix: 1
81: args: -eps_type {{krylovschur subspace arnoldi gd}}
82: test:
83: suffix: 1_power
84: args: -eps_type power -eps_max_it 20000
85: test:
86: suffix: 1_gd2
87: args: -eps_type gd -eps_gd_double_expansion
88: test:
89: suffix: 1_arpack
90: args: -eps_type arpack
91: requires: arpack
92: test:
93: suffix: 1_trlan
94: args: -eps_type trlan
95: requires: trlan
97: TEST*/