LPnetlib/lpi_cplex1
Netlib LP problem cplex1: minimize c'*x, where Ax=b, lo<=x<=hi
Name 
lpi_cplex1 
Group 
LPnetlib 
Matrix ID 
710 
Num Rows

3,005 
Num Cols

5,224 
Nonzeros

10,947 
Pattern Entries

10,947 
Kind

Linear Programming Problem 
Symmetric

No 
Date

1993 
Author

E. Klotz 
Editor

J. Chinneck 
Structural Rank 
3,005 
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 
2.000065e+02 
Minimum Singular Value 
6.386641e02 
Condition Number 
3.131639e+03

Rank 
3,005 
sprank(A)rank(A) 
0 
Null Space Dimension 
0 
Full Numerical Rank? 
yes 
Download Singular Values 
MATLAB

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MATLAB
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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

CPLEX1, CPLEX2: medium and large problems respectively. CPLEX1
referred to as CPLEX problem in Chinneck [1993], and is remarkably
nonvolatile, showing a single small IIS regardless of the IIS algorithm
applied. CPLEX2 is an almostfeasible problem. Contributor: Ed Klotz,
CPLEX Optimization Inc.
Name Rows Cols Nonzeros Bounds Notes
cplex1 3006 3221 10664 B dense col (> 1500)
REFERENCES

J.W. Chinneck (1993). "Finding the Most Useful Subset of Constraints
for Analysis in an Infeasible Linear Program", technical report
SCE9307, Systems and Computer Engineering, Carleton University,
Ottawa, Canada.
