| Matrix properties | |
| number of rows | 68,121 |
| number of columns | 68,121 |
| nonzeros | 5,377,761 |
| structural full rank? | yes |
| structural rank | 68,121 |
| # of blocks from dmperm | 1 |
| # strongly connected comp. | 1 |
| entries not in dmperm blocks | 0 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | 30% |
| numeric value symmetry | 0% |
| type | real |
| structure | unsymmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | B. Muite |
| editor | T. Davis |
| date | 2007 |
| kind | structural problem |
| 2D/3D problem? | yes |
Notes:
Chebyshev integration matrix from Benson Muite, Oxford. Details of the matrices can be found in a preprint at http://www.maths.ox.ac.uk/~muite entitled "A comparison of Chebyshev methods for solving fourth-order semilinear initial boundary value problems," June 2007. These matrices are very ill-conditioned, partly because of the dense rows which are hard to scale when coupled with the rest of the matrix.
| Ordering statistics: | AMD | METIS |
| nnz(chol(P*(A+A'+s*I)*P')) | 22,994,095 | 28,833,628 |
| Cholesky flop count | 1.6e+10 | 3.6e+10 |
| nnz(L+U), no partial pivoting | 45,920,069 | 57,599,135 |
| nnz(V) for QR, upper bound nnz(L) for LU | 70,638,345 | - |
| nnz(R) for QR, upper bound nnz(U) for LU | 2.320269e+09 | - |
Maintained by Tim Davis, last updated 04-May-2008.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.