Matrix: HB/fs_680_2
Description: UNSYMMETRIC FACSIMILE CONVERGENCE MATRIX
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| (bipartite graph drawing) | (graph drawing of A+A') |
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| Matrix properties | |
| number of rows | 680 |
| number of columns | 680 |
| nonzeros | 2,424 |
| structural full rank? | yes |
| structural rank | 680 |
| # of blocks from dmperm | 446 |
| # strongly connected comp. | 446 |
| explicit zero entries | 222 |
| nonzero pattern symmetry | 51% |
| numeric value symmetry | 0% |
| type | real |
| structure | unsymmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | A. Curtis |
| editor | I. Duff, R. Grimes, J. Lewis |
| date | 1983 |
| kind | subsequent 2D/3D problem |
| 2D/3D problem? | yes |
Notes:
next: HB/fs_680_3 first: HB/fs_680_1
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 2,620 |
| Cholesky flop count | 1.4e+04 |
| nnz(L+U), no partial pivoting, with AMD | 4,560 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 2,056 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 3,971 |
Note that all matrix statistics (except nonzero pattern symmetry) exclude the 222 explicit zero entries.
| SVD-based statistics: | |
| norm(A) | 7.19085e+13 |
| min(svd(A)) | 4.899e+08 |
| cond(A) | 146782 |
| rank(A) | 680 |
| sprank(A)-rank(A) | 0 |
| null space dimension | 0 |
| full numerical rank? | yes |
| singular values (MAT file): | click here |
| SVD method used: | s = svd (full (A)) ; |
| status: | ok |
For a description of the statistics displayed above, click here.
Maintained by Tim Davis, last updated 12-Mar-2014.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.