Matrix: Pothen/tandem_vtx
Description: tandem_vtx, with coordinates. From NASA, collected by Alex Pothen
| Matrix properties | |
| number of rows | 18,454 |
| number of columns | 18,454 |
| nonzeros | 253,350 |
| structural full rank? | yes |
| structural rank | 18,454 |
| # of blocks from dmperm | 1 |
| # strongly connected comp. | 1 |
| entries not in dmperm blocks | 0 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | symmetric |
| numeric value symmetry | symmetric |
| type | binary |
| structure | symmetric |
| Cholesky candidate? | yes |
| positive definite? | no |
| author | NASA |
| editor | G. Kumfert, A. Pothen |
| date | 2003 |
| kind | structural problem |
| 2D/3D problem? | yes |
| Additional fields | size and type |
| coord | full 18454-by-3 |
| Ordering statistics: | AMD | METIS |
| nnz(chol(P*(A+A'+s*I)*P')) | 2,697,614 | 1,964,597 |
| Cholesky flop count | 1.0e+09 | 4.3e+08 |
| nnz(L+U), no partial pivoting | 5,376,774 | 3,910,740 |
| nnz(V) for QR, upper bound nnz(L) for LU | 4,783,934 | 3,613,382 |
| nnz(R) for QR, upper bound nnz(U) for LU | 9,113,158 | 7,225,875 |
Maintained by Tim Davis, last updated 30-Sep-2008.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.