Actual source code: test42.c
slepc-3.16.2 2022-02-01
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-2021, 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[] = "Block-diagonal orthogonal eigenproblem.\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: EPS eps;
21: Mat A;
22: PetscRandom rand;
23: PetscScalar val,c,s;
24: PetscInt n=30,i,seed=0x12345678;
25: PetscMPIInt rank;
28: SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
29: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
30: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
31: PetscPrintf(PETSC_COMM_WORLD,"\nOrthogonal eigenproblem, n=%D\n\n",n);
33: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
34: Generate the matrix
35: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
37: PetscRandomCreate(PETSC_COMM_WORLD,&rand);
38: PetscRandomSetFromOptions(rand);
39: PetscOptionsGetInt(NULL,NULL,"-seed",&seed,NULL);
40: PetscRandomSetSeed(rand,seed);
41: PetscRandomSeed(rand);
42: PetscRandomSetInterval(rand,0,2*PETSC_PI);
44: MatCreate(PETSC_COMM_WORLD,&A);
45: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
46: MatSetFromOptions(A);
47: MatSetUp(A);
49: if (!rank) {
50: for (i=0;i<n/2;i++) {
51: PetscRandomGetValue(rand,&val);
52: c = PetscCosReal(PetscRealPart(val));
53: s = PetscSinReal(PetscRealPart(val));
54: MatSetValue(A,2*i,2*i,c,INSERT_VALUES);
55: MatSetValue(A,2*i+1,2*i+1,c,INSERT_VALUES);
56: MatSetValue(A,2*i,2*i+1,s,INSERT_VALUES);
57: MatSetValue(A,2*i+1,2*i,-s,INSERT_VALUES);
58: }
59: if (n%2) { MatSetValue(A,n-1,n-1,-1.0,INSERT_VALUES); }
60: }
61: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
62: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
64: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
65: Create the eigensolver and solve the problem
66: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
68: EPSCreate(PETSC_COMM_WORLD,&eps);
69: EPSSetOperators(eps,A,NULL);
70: EPSSetProblemType(eps,EPS_NHEP);
71: EPSSetWhichEigenpairs(eps,EPS_LARGEST_REAL);
72: EPSSetFromOptions(eps);
73: EPSSolve(eps);
75: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
76: Display solution and clean up
77: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
79: EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);
80: EPSDestroy(&eps);
81: MatDestroy(&A);
82: PetscRandomDestroy(&rand);
83: SlepcFinalize();
84: return ierr;
85: }
87: /*TEST
89: testset:
90: requires: complex !single
91: args: -eps_type ciss -eps_all -rg_type ring -rg_ring_center 0 -rg_ring_radius 1 -rg_ring_width 0.05 -rg_ring_startangle .93 -rg_ring_endangle .07
92: filter: sed -e "s/[+-]\([0-9]\.[0-9]*i\)/+-\\1/g"
93: test:
94: suffix: 1_ring
95: args: -eps_ciss_extraction {{ritz hankel}}
97: TEST*/