Matrix: Nemeth/nemeth26
Description: Newton-Schultz iteration, Z_k+1=Z_k+(1/2)*(I-(Z_k)^2)*Z_k. This is Z_26
| Matrix properties | |
| number of rows | 9,506 |
| number of columns | 9,506 |
| nonzeros | 1,511,760 |
| structural full rank? | yes |
| structural rank | 9,506 |
| # 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 | real |
| structure | symmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | K. Nemeth |
| editor | T. Davis |
| date | 1999 |
| kind | subsequent theoretical/quantum chemistry problem |
| 2D/3D problem? | no |
Notes:
next: - first: Nemeth/nemeth01
| Ordering statistics: | AMD | METIS |
| nnz(chol(P*(A+A'+s*I)*P')) | 798,380 | 1,826,130 |
| Cholesky flop count | 6.7e+07 | 3.7e+08 |
| nnz(L+U), no partial pivoting | 1,587,254 | 3,642,754 |
| nnz(V) for QR, upper bound nnz(L) for LU | 827,283 | 2,264,648 |
| nnz(R) for QR, upper bound nnz(U) for LU | 1,749,823 | 3,870,507 |
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.