Actual source code: test6.c
slepc-3.11.2 2019-07-30
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-2019, 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=1000*PETSC_MACHINE_EPSILON;
25: PetscInt n=30,i,Istart,Iend,seed=0x12345678;
28: SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
30: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
31: PetscPrintf(PETSC_COMM_WORLD,"\nDiagonal Eigenproblem, n=%D\n\n",n);
33: MatCreate(PETSC_COMM_WORLD,&A);
34: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
35: MatSetFromOptions(A);
36: MatSetUp(A);
37: MatGetOwnershipRange(A,&Istart,&Iend);
38: for (i=Istart;i<Iend;i++) {
39: MatSetValue(A,i,i,i+1,INSERT_VALUES);
40: }
41: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
42: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
44: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
45: Solve the eigensystem
46: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
47: EPSCreate(PETSC_COMM_WORLD,&eps);
48: EPSSetOperators(eps,A,NULL);
49: EPSSetProblemType(eps,EPS_HEP);
50: EPSSetTolerances(eps,tol,PETSC_DEFAULT);
51: EPSSetFromOptions(eps);
52: /* set random initial vector */
53: MatCreateVecs(A,&v0,NULL);
54: PetscRandomCreate(PETSC_COMM_WORLD,&rand);
55: PetscRandomSetFromOptions(rand);
56: PetscOptionsGetInt(NULL,NULL,"-seed",&seed,NULL);
57: PetscRandomSetSeed(rand,seed);
58: PetscRandomSeed(rand);
59: VecSetRandom(v0,rand);
60: EPSSetInitialSpace(eps,1,&v0);
61: /* call the solver */
62: EPSSolve(eps);
64: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
65: Display solution and clean up
66: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
67: EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);
68: EPSDestroy(&eps);
69: MatDestroy(&A);
70: VecDestroy(&v0);
71: PetscRandomDestroy(&rand);
72: SlepcFinalize();
73: return ierr;
74: }
76: /*TEST
78: testset:
79: args: -eps_nev 4
80: requires: !single
81: output_file: output/test6_1.out
82: test:
83: suffix: 1
84: args: -eps_type {{krylovschur subspace arnoldi gd}}
85: test:
86: suffix: 1_power
87: args: -eps_type power -eps_max_it 20000
88: test:
89: suffix: 1_gd2
90: args: -eps_type gd -eps_gd_double_expansion
91: test:
92: suffix: 1_arpack
93: args: -eps_type arpack
94: requires: arpack
95: test:
96: suffix: 1_trlan
97: args: -eps_type trlan
98: requires: trlan
100: TEST*/