ngraph.sparse-collection
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Subset of the University of Florida sparse matrix collection
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# LPnetlib/lp_modszk1
UF Sparse Matrix Collection, Tim Davis
http://www.cise.ufl.edu/research/sparse/matrices/LPnetlib/lp_modszk1
[Netlib LP problem modszk1: minimize c'*x, where Ax=b, lo<=x<=hi]
id: 644
date: 1994
author: I. Maros
ed: D. Gay
fields: title name A b id aux kind date author ed notes
aux: c lo hi z0
kind: linear programming problem
notes:
A Netlib LP problem, in lp/data. For more information
send email to netlib.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 right-hand side vector, but include
the cost row. We have omitted other free rows and all but the first
right-hand 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 BOUND-TYPE 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
BOUND-TYPE TABLE
MODSZK1 FR
From Istvan Maros.
Concerning the problems he submitted, Istvan Maros says that
MODSZK1 is a "real-life 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 multi-sector 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
