LPnetlib/lp_shell
Netlib LP problem shell: minimize c'*x, where Ax=b, lo<=x<=hi
Name 
lp_shell 
Group 
LPnetlib 
Matrix ID 
683 
Num Rows

536 
Num Cols

1,777 
Nonzeros

3,558 
Pattern Entries

3,558 
Kind

Linear Programming Problem 
Symmetric

No 
Date

1978 
Author

J. Reid 
Editor

D. Gay 
Structural Rank 
536 
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

integer 
SVD Statistics 
Matrix Norm 
1.600042e+01 
Minimum Singular Value 
1.578462e14 
Condition Number 
1.013672e+15

Rank 
535 
sprank(A)rank(A) 
1 
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

This LP problem is the source of three sparse matrices in the Harwell/Boeing
sparse matrix collection: SHL_0, SHL_200, and SHL_400. Those three matrices
are square, nonsingular basis matrices that occured during the solution of
SHELL.

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
SHELL 537 1775 4900 38049 B 1.2088253460E+09
BOUNDTYPE TABLE
SHELL UP LO FX
From John Reid.
