qap (version 0.1-0)

read_qaplib: Read QAPLIB Files

Description

Reads example file in the format used by QAPLIB.

Usage

read_qaplib(file)

Arguments

file

file name.

Value

Returns a list with the components

D

distance matrix.

W

weight matrix.

solution

a known optimal solution (if available).

opt

known optimal value (if available).

Details

Problems end with the extension .dat and solutions with .sln. The code tries to read the problem and, if available in the same directory, it also reads the solution and the known optimal value from the solution file.

The package contains a copy of the problem instances and solutions from QAPLIB. The data is stored in the package in directory qaplib.

References

R.E. Burkard, E. Cela, S.E. Karisch and F. Rendl, QAPLIB - A Quadratic Assignment Problem Library, http://anjos.mgi.polymtl.ca/qaplib/

Examples

## load a QAPLIB problem instance
p <- read_qaplib(system.file("qaplib", "had12.dat", package="qap"))
p

## list all QAPLIB instances
dir(system.file("qaplib", package="qap"), pattern = "*.dat")