Matrix: ATandT/twotone
Description: AT&T,harmonic balance method, two-tone. More off-diag nz than onetone
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| (bipartite graph drawing) | (graph drawing of A+A') |
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| Matrix properties | |
| number of rows | 120,750 |
| number of columns | 120,750 |
| nonzeros | 1,206,265 |
| structural full rank? | yes |
| structural rank | 120,750 |
| # of blocks from dmperm | 13,135 |
| # strongly connected comp. | 5 |
| explicit zero entries | 17,959 |
| nonzero pattern symmetry | 24% |
| numeric value symmetry | 11% |
| type | real |
| structure | unsymmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | R. Melville, D. Long |
| editor | T. Davis |
| date | 2001 |
| kind | frequency-domain circuit simulation problem |
| 2D/3D problem? | no |
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 33,508,325 |
| Cholesky flop count | 6.8e+10 |
| nnz(L+U), no partial pivoting, with AMD | 66,895,900 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 7,437,600 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 20,926,670 |
Note that all matrix statistics (except nonzero pattern symmetry) exclude the 17959 explicit zero entries.
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.