Matrix: HB/lns_3937
Description: UNSYMMETRIC MATRIX FROM I.P.J. DEC 1982. LINEARIZED N-S. COMPRESSIBLE
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| (bipartite graph drawing) | (graph drawing of A+A') |
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| Matrix properties | |
| number of rows | 3,937 |
| number of columns | 3,937 |
| nonzeros | 25,407 |
| structural full rank? | yes |
| structural rank | 3,937 |
| # of blocks from dmperm | 351 |
| # strongly connected comp. | 290 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | 85% |
| numeric value symmetry | 0% |
| type | real |
| structure | unsymmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | I. Jones |
| editor | I. Duff, R. Grimes, J. Lewis |
| date | 1982 |
| kind | computational fluid dynamics problem |
| 2D/3D problem? | yes |
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 106,263 |
| Cholesky flop count | 7.4e+06 |
| nnz(L+U), no partial pivoting, with AMD | 208,589 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 184,022 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 383,950 |
| SVD-based statistics: | |
| norm(A) | 3.26618e+11 |
| min(svd(A)) | 1.63413e-05 |
| cond(A) | 1.99873e+16 |
| rank(A) | 2,895 |
| sprank(A)-rank(A) | 1,042 |
| null space dimension | 1,042 |
| full numerical rank? | no |
| singular value gap | 1.02543 |
| singular values (MAT file): | click here |
| SVD method used: | s = svd (full (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.