Matrix: Meszaros/dbir1

Description: linear programming problem, C. Meszaros test set

 (bipartite graph drawing)

• Matrix group: Meszaros
• download as a MATLAB mat-file, file size: 830 KB. Use UFget(1705) or UFget('Meszaros/dbir1') in MATLAB.

 Matrix properties number of rows 18,804 number of columns 45,775 nonzeros 1,077,025 structural full rank? no structural rank 18,802 # of blocks from dmperm 2 # strongly connected comp. 2,339 explicit zero entries 0 nonzero pattern symmetry 0% numeric value symmetry 0% type integer structure rectangular Cholesky candidate? no positive definite? no

 author editor C. Meszaros date 2004 kind linear programming problem 2D/3D problem? no

 Additional fields size and type b full 18804-by-1 c full 45775-by-1 lo full 45775-by-1 hi full 45775-by-1 z0 full 1-by-1

Notes:

```http://www.sztaki.hu/~meszaros/public_ftp/lptestset
Converted to standard form via Resende and Veiga's mpsrd:
minimize c'*x, subject to A*x=b and lo <= x <= hi
```

 Ordering statistics: result nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD 39,796,562 nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD 2,849,474

 SVD-based statistics: norm(A) 4.4319e+07 min(svd(A)) 0 cond(A) Inf rank(A) 18,512 sprank(A)-rank(A) 290 null space dimension 292 full numerical rank? no singular value gap 44846.2

 singular values (MAT file): click here SVD method used: s = svd (full (R)) ; where [~,R,E] = spqr (A') with droptol of zero status: ok