Matrix: Mittelmann/rail507

Description: Italian railways (H. Mittelmann test set)

 (bipartite graph drawing)

• Matrix group: Mittelmann
• download as a MATLAB mat-file, file size: 337 KB. Use UFget(1654) or UFget('Mittelmann/rail507') in MATLAB.

 Matrix properties number of rows 507 number of columns 63,516 nonzeros 409,856 structural full rank? yes structural rank 507 # of blocks from dmperm 1 # strongly connected comp. 1 explicit zero entries 0 nonzero pattern symmetry 0% numeric value symmetry 0% type integer structure rectangular Cholesky candidate? no positive definite? no

 author P. Nobili editor J. Beasley date 2005 kind linear programming problem 2D/3D problem? no

 Additional fields size and type b full 507-by-1 c full 63516-by-1 lo full 63516-by-1 hi full 63516-by-1 z0 full 1-by-1

Notes:

```Hans Mittelmann test set, http://plato.asu.edu/ftp/lptestset
minimize c'*x, subject to A*x=b and lo <= x <= hi

RAIL: set covering problems from the Italian railroad, see
http://people.brunel.ac.uk/~mastjjb/jeb/orlib/scpinfo.html
```

 Ordering statistics: result nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD 20,526,974 nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD 97,026

 SVD-based statistics: norm(A) 149.326 min(svd(A)) 1 cond(A) 149.326 rank(A) 507 sprank(A)-rank(A) 0 null space dimension 0 full numerical rank? yes

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

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.