Matrix: VanVelzen/Zd_Jac2_db
Description: Chemical process simulation, Nils van Velzen (diagonal blocks only)
![]() |
![]() |
| (bipartite graph drawing) | (graph drawing of A+A') |
![]() |
![]() |
| Matrix properties | |
| number of rows | 22,835 |
| number of columns | 22,835 |
| nonzeros | 676,439 |
| structural full rank? | yes |
| structural rank | 22,835 |
| # of blocks from dmperm | 9,833 |
| # strongly connected comp. | 9,833 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | 30% |
| numeric value symmetry | 0% |
| type | real |
| structure | unsymmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | N. van Velzen |
| editor | T. Davis |
| date | 2006 |
| kind | chemical process simulation problem |
| 2D/3D problem? | no |
| Additional fields | size and type |
| b | full 22835-by-1 |
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 3,285,210 |
| Cholesky flop count | 2.0e+09 |
| nnz(L+U), no partial pivoting, with AMD | 6,547,585 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 1,629,609 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 3,910,842 |
| SVD-based statistics: | |
| norm(A) | 1.37636e+09 |
| min(svd(A)) | 2.31934e-10 |
| cond(A) | 5.93429e+18 |
| rank(A) | 22,360 |
| sprank(A)-rank(A) | 475 |
| null space dimension | 475 |
| full numerical rank? | no |
| singular value gap | 1.03432 |
| singular values (MAT file): | click here |
| SVD method used: | s = svd (full (R)) ; where [~,R,E] = spqr (A) with droptol of zero |
| 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.