Matrix: Schenk_IBMNA/c-67b
Description: IBM TJ Watson, non-linear optimization
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| Matrix properties | |
| number of rows | 57,975 |
| number of columns | 57,975 |
| nonzeros | 530,583 |
| structural full rank? | yes |
| structural rank | 57,975 |
| # of blocks from dmperm | 165 |
| # strongly connected comp. | 165 |
| explicit zero entries | 1,352 |
| nonzero pattern symmetry | symmetric |
| numeric value symmetry | symmetric |
| type | real |
| structure | symmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | IBM |
| editor | O. Schenk |
| date | 2006 |
| kind | subsequent optimization problem |
| 2D/3D problem? | no |
| Additional fields | size and type |
| b | full 57975-by-1 |
Notes:
next: - first: Schenk_IBMNA/c-67 An earlier version (Oct. 2003) of this matrix was obtained from Olaf Schenk, and appears here as Schenk_IBMNA/c-67. However, it differs from the version posted on his web site as of Nov. 2006. The new version appears here as Schenk_IBMNA/c-67b. The two matrices are very similar, but not identical.
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 441,401 |
| Cholesky flop count | 1.0e+07 |
| nnz(L+U), no partial pivoting, with AMD | 824,827 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 28,894,835 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 46,391,127 |
Note that all matrix statistics (except nonzero pattern symmetry) exclude the 1352 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.