Matrix: HB/jpwh_991
Description: UNSYMMETRIC MATRIX FROM PHILIPS LTD, J.P.WHELAN,1978.
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| (bipartite graph drawing) | (graph drawing of A+A') |
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| Matrix properties | |
| number of rows | 991 |
| number of columns | 991 |
| nonzeros | 6,027 |
| structural full rank? | yes |
| structural rank | 991 |
| # of blocks from dmperm | 146 |
| # strongly connected comp. | 146 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | 94% |
| numeric value symmetry | 94% |
| type | integer |
| structure | unsymmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | J. Whelan |
| editor | I. Duff, R. Grimes, J. Lewis |
| date | 1978 |
| kind | semiconductor device problem |
| 2D/3D problem? | yes |
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 28,358 |
| Cholesky flop count | 2.2e+06 |
| nnz(L+U), no partial pivoting, with AMD | 55,725 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 65,321 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 117,974 |
| SVD-based statistics: | |
| norm(A) | 16.292 |
| min(svd(A)) | 0.114696 |
| cond(A) | 142.045 |
| rank(A) | 991 |
| 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.