**Matrix: LPnetlib/lp_truss**

Description: Netlib LP problem truss: minimize c'*x, where Ax=b, lo<=x<=hi

(bipartite graph drawing) |

Matrix properties | |

number of rows | 1,000 |

number of columns | 8,806 |

nonzeros | 27,836 |

structural full rank? | yes |

structural rank | 1,000 |

# of blocks from dmperm | 1 |

# strongly connected comp. | 1 |

explicit zero entries | 0 |

nonzero pattern symmetry | 0% |

numeric value symmetry | 0% |

type | real |

structure | rectangular |

Cholesky candidate? | no |

positive definite? | no |

author | M. Ferris |

editor | D. Gay |

date | 1990 |

kind | linear programming problem |

2D/3D problem? | no |

Additional fields | size and type |

b | full 1000-by-1 |

c | full 8806-by-1 |

lo | full 8806-by-1 |

hi | full 8806-by-1 |

z0 | full 1-by-1 |

Notes:

A Netlib LP problem, from a generator in lp/data. For more information send email to netlib@ornl.gov with the message: send index from lp send readme from lp/data This copy of TRUSS was created by the TRUSS generator program, on an Sun UltraSparc, on May 15, 1997. The following are relevant excerpts from lp/data/readme (by David M. Gay): The column and nonzero counts in the PROBLEM SUMMARY TABLE below exclude slack and surplus columns and the right-hand side vector, but include the cost row. We have omitted other free rows and all but the first right-hand side vector, as noted below. The byte count is for the MPS compressed file; it includes a newline character at the end of each line. These files start with a blank initial line intended to prevent mail programs from discarding any of the data. The BR column indicates whether a problem has bounds or ranges: B stands for "has bounds", R for "has ranges". The optimal value is from MINOS version 5.3 (of Sept. 1988) running on a VAX with default options. PROBLEM SUMMARY TABLE Name Rows Cols Nonzeros Bytes BR Optimal Value TRUSS 1001 8806 36642 (see NOTES) 4.5881584719E+05 Source: At the request of Olvi Mangasarian, Rudy Setiono supplied the generator and description (both written by Michael Ferris) and data for TRUSS. Requesting TRUSS will get you a bundle of Fortran source and data for generating an MPS file for TRUSS, a problem of minimizing the weight of a certain structure. The bundle also includes a description of the problem. Added to Netlib on 26 Feb. 1990

Ordering statistics: | result |

nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 1,647,142 |

nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 51,088 |

SVD-based statistics: | |

norm(A) | 5.60315 |

min(svd(A)) | 0.0117431 |

cond(A) | 477.144 |

rank(A) | 1,000 |

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 (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.
*