Matrix: NYPA/Maragal_7
Description: Rank deficient least squares problem, D. Maragal, NY Power Authority
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| Matrix properties | |
| number of rows | 46,845 |
| number of columns | 26,564 |
| nonzeros | 1,200,537 |
| structural full rank? | no |
| structural rank | 25,866 |
| # of blocks from dmperm | 1,294 |
| # strongly connected comp. | 41 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | 0% |
| numeric value symmetry | 0% |
| type | real |
| structure | rectangular |
| Cholesky candidate? | no |
| positive definite? | no |
| author | D. Maragal |
| editor | T. Davis |
| date | 2008 |
| kind | least squares problem |
| 2D/3D problem? | no |
| Additional fields | size and type |
| b | full 46845-by-1 |
Notes:
rank deficient (rank(A) < sprank(A) < size(A,2)) sprank: 25866 columns: 26564
| Ordering statistics: | result |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 241,876,349 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 232,203,788 |
| SVD-based statistics: | |
| norm(A) | 13.3284 |
| min(svd(A)) | 0 |
| cond(A) | Inf |
| rank(A) | 20,843 |
| sprank(A)-rank(A) | 5,023 |
| null space dimension | 5,721 |
| full numerical rank? | no |
| singular value gap | 1.12841e+08 |
| 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.