LPnetlib/lpi_itest2
Netlib LP problem itest2: minimize c'*x, where Ax=b, lo<=x<=hi
Name 
lpi_itest2 
Group 
LPnetlib 
Matrix ID 
719 
Num Rows

9 
Num Cols

13 
Nonzeros

26 
Pattern Entries

26 
Kind

Linear Programming Problem 
Symmetric

No 
Date

1991 
Author

J. Chinneck, E. Dravnieks 
Editor

J. Chinneck 
Structural Rank 
9 
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 
4.226048e+00 
Minimum Singular Value 
1 
Condition Number 
4.226048e+00

Rank 
9 
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

ITEST6, ITEST2: very small problems having numerous clustered IISs.
These match problems 1 and 2, respectively, in Chinneck and Dravnieks
[1991]. Contributors: J.W. Chinneck and E.W. Dravnieks, Carleton
University.
Name Rows Cols Nonzeros Bounds Notes
itest2 10 4 17
REFERENCES

J.W. Chinneck and E.W. Dravnieks (1991). "Locating Minimal Infeasible
Constraint Sets in Linear Programs", ORSA Journal on Computing, Volume
3, No. 2.
