Matrix: HB/will199
Description: UNSYMMETRIC PATTERN OF ORDER 199 GIVEN BY WILLOUGHBY IN REID, 1970
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| (bipartite graph drawing) | (graph drawing of A+A') |
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| Matrix properties | |
| number of rows | 199 |
| number of columns | 199 |
| nonzeros | 701 |
| structural full rank? | yes |
| structural rank | 199 |
| # of blocks from dmperm | 10 |
| # strongly connected comp. | 1 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | 6% |
| numeric value symmetry | 6% |
| type | binary |
| structure | unsymmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | R. Willoughby |
| editor | I. Duff, R. Grimes, J. Lewis |
| date | 1979 |
| kind | structural problem |
| 2D/3D problem? | yes |
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 4,595 |
| Cholesky flop count | 1.9e+05 |
| nnz(L+U), no partial pivoting, with AMD | 8,991 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 1,230 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 2,403 |
| SVD-based statistics: | |
| norm(A) | 4.38808 |
| min(svd(A)) | 7.39959e-18 |
| cond(A) | 5.93016e+17 |
| rank(A) | 191 |
| sprank(A)-rank(A) | 8 |
| null space dimension | 8 |
| full numerical rank? | no |
| singular value gap | 4.90955e+13 |
| 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.