| Matrix properties | |
| number of rows | 76,638 |
| number of columns | 76,638 |
| nonzeros | 859,520 |
| structural full rank? | yes |
| structural rank | 76,638 |
| # of blocks from dmperm | 18 |
| # strongly connected comp. | 18 |
| entries not in dmperm blocks | 51 |
| explicit zero entries | 34 |
| nonzero pattern symmetry | symmetric |
| numeric value symmetry | symmetric |
| type | real |
| structure | symmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | IBM |
| editor | O. Schenk |
| date | 2004 |
| kind | optimization problem |
| 2D/3D problem? | no |
| Additional fields | size and type |
| b | full 76638-by-1 |
Notes:
Revised Nov 2006; relative eps changes to A, right-hand-side added. Note that this matrix should have been placed in the Schenk_IBMNA/ directory when it was first added in August 2004, but moving it now would disrupt exising users of the collection.
| Ordering statistics: | AMD | METIS | DMPERM+ |
| nnz(chol(P*(A+A'+s*I)*P')) | 19,945,308 | 12,458,222 | 12,465,479 |
| Cholesky flop count | 5.7e+10 | 1.8e+10 | 1.8e+10 |
| nnz(L+U), no partial pivoting | 39,813,978 | 24,839,806 | 24,854,371 |
| nnz(V) for QR, upper bound nnz(L) for LU | 128,102,620 | - | 128,102,586 |
| nnz(R) for QR, upper bound nnz(U) for LU | 201,580,038 | - | 201,580,055 |
Note that all matrix statistics (except nonzero pattern symmetry) exclude the 34 explicit zero entries.
Maintained by Tim Davis, last updated 04-May-2008.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.