Matrix: HB/lock1074
Description: FINITE ELEMENT PROBLEM. LOCKHEED GYRO PROBLEM
![]() |
| (undirected graph drawing) |
![]() |
![]() |
![]() |
| Matrix properties | |
| number of rows | 1,074 |
| number of columns | 1,074 |
| nonzeros | 51,588 |
| structural full rank? | no |
| structural rank | 1,038 |
| # of blocks from dmperm | 3 |
| # strongly connected comp. | 37 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | symmetric |
| numeric value symmetry | symmetric |
| type | binary |
| structure | symmetric |
| Cholesky candidate? | no |
| positive definite? | no |
| author | W. Loden |
| editor | I. Duff, R. Grimes, J. Lewis |
| date | 1980 |
| kind | structural problem |
| 2D/3D problem? | yes |
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 60,693 |
| Cholesky flop count | 4.2e+06 |
| nnz(L+U), no partial pivoting, with AMD | 120,312 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 68,223 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 132,045 |
| SVD-based statistics: | |
| norm(A) | 57.2283 |
| min(svd(A)) | 0 |
| cond(A) | Inf |
| rank(A) | 155 |
| sprank(A)-rank(A) | 883 |
| null space dimension | 919 |
| full numerical rank? | no |
| singular value gap | 5.19122e+11 |
| 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.