LPnetlib/lp_modszk1
Netlib LP problem modszk1: minimize c'*x, where Ax=b, lo<=x<=hi
Name 
lp_modszk1 
Group 
LPnetlib 
Matrix ID 
644 
Num Rows

687 
Num Cols

1,620 
Nonzeros

3,168 
Pattern Entries

3,168 
Kind

Linear Programming Problem 
Symmetric

No 
Date

1994 
Author

I. Maros 
Editor

D. Gay 
Structural Rank 
686 
Structural Rank Full 
false 
Num Dmperm Blocks

3 
Strongly Connect Components

3 
Num Explicit Zeros

0 
Pattern Symmetry

0% 
Numeric Symmetry

0% 
Cholesky Candidate

no 
Positive Definite

no 
Type

real 
SVD Statistics 
Matrix Norm 
4.875560e+00 
Minimum Singular Value 
9.119891e20 
Condition Number 
5.346073e+19

Rank 
686 
sprank(A)rank(A) 
0 
Null Space Dimension 
1 
Full Numerical Rank? 
no 
Download Singular Values 
MATLAB

Download 
MATLAB
Rutherford Boeing
Matrix Market

Notes 
A Netlib LP problem, in lp/data. For more information
send email to netlib@ornl.gov with the message:
send index from lp
send readme from lp/data
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 righthand side vector, but include
the cost row. We have omitted other free rows and all but the first
righthand 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 BOUNDTYPE TABLE below shows the bound types
present in those problems that have bounds.
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
MODSZK1 688 1620 4158 40908 B 3.2061972906E+02
BOUNDTYPE TABLE
MODSZK1 FR
From Istvan Maros.
Concerning the problems he submitted, Istvan Maros says that
MODSZK1 is a "reallife problem" that
is "very degenerate" and on which a dual simplex algorithm "may require
up to 10 times" fewer iterations than a primal simplex algorithm. It
"is a multisector economic planning model (a kind of an input/output
model in economy)" and "is an old problem of mine and it is not easy to
recall more."
Added to Netlib on 17 Jan. 1994
