Actual source code: test6.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[] = "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: PetscFunctionBeginUser;
28: PetscCall(SlepcInitialize(&argc,&argv,(char*)0,help));
30: PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
31: PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nDiagonal Eigenproblem, n=%" PetscInt_FMT "\n\n",n));
33: PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
34: PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n));
35: PetscCall(MatSetFromOptions(A));
36: PetscCall(MatSetUp(A));
37: PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
38: for (i=Istart;i<Iend;i++) PetscCall(MatSetValue(A,i,i,i+1,INSERT_VALUES));
39: PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
40: PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
42: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
43: Solve the eigensystem
44: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
45: PetscCall(EPSCreate(PETSC_COMM_WORLD,&eps));
46: PetscCall(EPSSetOperators(eps,A,NULL));
47: PetscCall(EPSSetProblemType(eps,EPS_HEP));
48: PetscCall(EPSSetTolerances(eps,tol,PETSC_DEFAULT));
49: PetscCall(EPSSetFromOptions(eps));
50: /* set random initial vector */
51: PetscCall(MatCreateVecs(A,&v0,NULL));
52: PetscCall(PetscRandomCreate(PETSC_COMM_WORLD,&rand));
53: PetscCall(PetscRandomSetFromOptions(rand));
54: PetscCall(PetscOptionsGetInt(NULL,NULL,"-seed",&seed,NULL));
55: PetscCall(PetscRandomSetSeed(rand,seed));
56: PetscCall(PetscRandomSeed(rand));
57: PetscCall(VecSetRandom(v0,rand));
58: PetscCall(EPSSetInitialSpace(eps,1,&v0));
59: /* call the solver */
60: PetscCall(EPSSolve(eps));
62: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
63: Display solution and clean up
64: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
65: PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL));
66: PetscCall(EPSDestroy(&eps));
67: PetscCall(MatDestroy(&A));
68: PetscCall(VecDestroy(&v0));
69: PetscCall(PetscRandomDestroy(&rand));
70: PetscCall(SlepcFinalize());
71: return 0;
72: }
74: /*TEST
76: testset:
77: args: -eps_nev 4
78: requires: !single
79: output_file: output/test6_1.out
80: test:
81: suffix: 1
82: args: -eps_type {{krylovschur subspace arnoldi gd}}
83: test:
84: suffix: 1_power
85: args: -eps_type power -eps_max_it 20000
86: test:
87: suffix: 1_gd2
88: args: -eps_type gd -eps_gd_double_expansion
89: test:
90: suffix: 1_arpack
91: args: -eps_type arpack
92: requires: arpack
93: test:
94: suffix: 1_trlan
95: args: -eps_type trlan
96: requires: trlan
98: TEST*/