Matrix: Rothberg/struct4
Description: Finite element matrix, from Ed Rothberg, Silicon Graphics, Inc.
|
| (undirected graph drawing) |
 |
| Matrix properties | |
| number of rows | 4,350 |
| number of columns | 4,350 |
| nonzeros | 237,798 |
| structural full rank? | yes |
| structural rank | 4,350 |
| # of blocks from dmperm | 1 |
| # strongly connected comp. | 1 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | symmetric |
| numeric value symmetry | symmetric |
| type | binary |
| structure | symmetric |
| Cholesky candidate? | yes |
| positive definite? | no |
| author | E. Rothberg |
| editor | T. Davis |
| date | 1997 |
| kind | structural problem |
| 2D/3D problem? | yes |
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 2,361,326 |
| Cholesky flop count | 2.0e+09 |
| nnz(L+U), no partial pivoting, with AMD | 4,718,302 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 1,851,785 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 3,321,077 |
| SVD-based statistics: | |
| norm(A) | 71.9473 |
| min(svd(A)) | 0.000993909 |
| cond(A) | 72388.3 |
| rank(A) | 4,350 |
| sprank(A)-rank(A) | 0 |
| null space dimension | 0 |
| full numerical rank? | yes |
| singular values (MAT file): | click here |
| SVD method used: | s = piro_band_svd (A) |
| status: | ok |
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.