Actual source code: test14.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[] = "Tests multiple calls to SVDSolve with equal matrix size.\n\n"
12: "The command line options are:\n"
13: " -m <m>, where <m> = matrix rows.\n"
14: " -n <n>, where <n> = matrix columns (defaults to m+2).\n\n";
16: #include <slepcsvd.h>
18: /*
19: This example computes the singular values of two rectangular bidiagonal matrices
21: | 1 2 | | 1 |
22: | 1 2 | | 2 1 |
23: | 1 2 | | 2 1 |
24: A = | . . | B = | . . |
25: | . . | | . . |
26: | 1 2 | | 2 1 |
27: | 1 2 | | 2 1 |
28: */
30: int main(int argc,char **argv)
31: {
32: Mat A,B;
33: SVD svd;
34: PetscInt m=20,n,Istart,Iend,i,col[2];
35: PetscScalar valsa[] = { 1, 2 }, valsb[] = { 2, 1 };
36: PetscBool flg;
38: SlepcInitialize(&argc,&argv,(char*)0,help);
39: PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL);
40: PetscOptionsGetInt(NULL,NULL,"-n",&n,&flg);
41: if (!flg) n=m+2;
42: PetscPrintf(PETSC_COMM_WORLD,"\nRectangular bidiagonal matrix, m=%" PetscInt_FMT " n=%" PetscInt_FMT "\n\n",m,n);
44: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
45: Generate the matrices
46: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
48: MatCreate(PETSC_COMM_WORLD,&A);
49: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m,n);
50: MatSetFromOptions(A);
51: MatSetUp(A);
52: MatGetOwnershipRange(A,&Istart,&Iend);
53: for (i=Istart;i<Iend;i++) {
54: col[0]=i; col[1]=i+1;
55: if (i<n-1) MatSetValues(A,1,&i,2,col,valsa,INSERT_VALUES);
56: else if (i==n-1) MatSetValue(A,i,col[0],valsa[0],INSERT_VALUES);
57: }
58: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
59: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
61: MatCreate(PETSC_COMM_WORLD,&B);
62: MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,m,n);
63: MatSetFromOptions(B);
64: MatSetUp(B);
65: MatGetOwnershipRange(B,&Istart,&Iend);
66: for (i=Istart;i<Iend;i++) {
67: col[0]=i-1; col[1]=i;
68: if (i==0) MatSetValue(B,i,col[1],valsb[1],INSERT_VALUES);
69: else if (i<n) MatSetValues(B,1,&i,2,col,valsb,INSERT_VALUES);
70: else if (i==n) MatSetValue(B,i,col[0],valsb[0],INSERT_VALUES);
71: }
72: MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
73: MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
75: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
76: Create the singular value solver, set options and solve
77: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
79: SVDCreate(PETSC_COMM_WORLD,&svd);
80: SVDSetOperators(svd,A,NULL);
81: SVDSetTolerances(svd,PETSC_DEFAULT,1000);
82: SVDSetFromOptions(svd);
83: SVDSolve(svd);
84: SVDErrorView(svd,SVD_ERROR_RELATIVE,NULL);
86: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
87: Solve with second matrix
88: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
90: SVDSetOperators(svd,B,NULL);
91: SVDSolve(svd);
92: SVDErrorView(svd,SVD_ERROR_RELATIVE,NULL);
94: /* Free work space */
95: SVDDestroy(&svd);
96: MatDestroy(&A);
97: MatDestroy(&B);
98: SlepcFinalize();
99: return 0;
100: }
102: /*TEST
104: testset:
105: args: -svd_nsv 3
106: requires: !single
107: output_file: output/test14_1.out
108: test:
109: suffix: 1
110: args: -svd_type {{lanczos trlanczos lapack}}
111: test:
112: suffix: 1_cross
113: args: -svd_type cross -svd_cross_explicitmatrix {{0 1}}
114: test:
115: suffix: 1_cyclic
116: args: -svd_type cyclic -svd_cyclic_explicitmatrix {{0 1}}
118: testset:
119: args: -n 18 -svd_nsv 3
120: requires: !single
121: output_file: output/test14_2.out
122: test:
123: suffix: 2
124: args: -svd_type {{lanczos trlanczos lapack}}
125: test:
126: suffix: 2_cross
127: args: -svd_type cross -svd_cross_explicitmatrix {{0 1}}
128: test:
129: suffix: 2_cyclic
130: args: -svd_type cyclic -svd_cyclic_explicitmatrix {{0 1}}
132: TEST*/