LPnetlib/lpi_forest6
Netlib LP problem forest6: minimize c'*x, where Ax=b, lo<=x<=hi
Name 
lpi_forest6 
Group 
LPnetlib 
Matrix ID 
714 
Num Rows

66 
Num Cols

131 
Nonzeros

246 
Pattern Entries

246 
Kind

Linear Programming Problem 
Symmetric

No 
Date

1993 
Author

H. Greenberg 
Editor

J. Chinneck 
Structural Rank 
66 
Structural Rank Full 
true 
Num Dmperm Blocks

1 
Strongly Connect Components

1 
Num Explicit Zeros

0 
Pattern Symmetry

0% 
Numeric Symmetry

0% 
Cholesky Candidate

no 
Positive Definite

no 
Type

real 
SVD Statistics 
Matrix Norm 
2.671478e+00 
Minimum Singular Value 
8.670271e01 
Condition Number 
3.081193e+00

Rank 
66 
sprank(A)rank(A) 
0 
Null Space Dimension 
0 
Full Numerical Rank? 
yes 
Download Singular Values 
MATLAB

Download 
MATLAB
Rutherford Boeing
Matrix Market

Notes 
An infeasible Netlib LP problem, in lp/infeas. For more information
send email to netlib@ornl.gov with the message:
send index from lp
send readme from lp/infeas
The lp/infeas directory contains infeasible linear programming test problems
collected by John W. Chinneck, Carleton Univ, Ontario Canada. The following
are relevant excerpts from lp/infeas/readme (by John W. Chinneck):
In the following, IIS stands for Irreducible Infeasible Subsystem, a set
of constraints which is itself infeasible, but becomes feasible when any
one member is removed. Isolating an IIS from within the larger set of
constraints defining the model is one analysis approach.
PROBLEM DESCRIPTION

FOREST6, WOODINFE: very small problems derived from networkbased
forestry models. The IIS in FOREST6 includes most of the rows.
WOODINFE is the example problem discussed in detail in Greenberg [1993],
and has a very small IIS. Contributor: H.J. Greenberg, University of
Colorado at Denver.
Name Rows Cols Nonzeros Bounds Notes
forest6 67 95 270 B
REFERENCES

H.J. Greenberg (1993). "A ComputerAssisted Analysis System for
Mathematical Programming Models and Solutions: A User's Guide for
ANALYZE", Kluwer Academic Publishers, Boston.
