ngraph.sparse-collection
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Subset of the University of Florida sparse matrix collection
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UF Sparse Matrix Collection, Tim Davis
http://www.cise.ufl.edu/research/sparse/matrices/LPnetlib/lp_shell
[]
id: 683
date: 1978
author: J. Reid
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@ornl.gov with the message:
send index from lp
send readme from lp/data
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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.
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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
SHELL 537 1775 4900 38049 B 1.2088253460E+09
BOUND-TYPE TABLE
SHELL UP LO FX
From John Reid.
