read_qaplib function

Read QAPLIB Files

Reads example file in the format used by QAPLIB.

read_qaplib(file)

Arguments

• file: file name.

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.

Returns

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).

References

R.E. Burkard, E. Cela, S.E. Karisch and F. Rendl, QAPLIB - A Quadratic Assignment Problem Library, https://www.opt.math.tugraz.at/qaplib/

Author(s)

Michael Hahsler

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")