# OR-Library

OR-Library is a collection of test data sets for a variety of OR problems.

A full list of the test data sets available in OR-Library can be found
here.

## Multidimensional knapsack problem

There are 11 data files.
The first data file is mknap1.
This data file contains 7 test problems which are
the test problems from C.C.Petersen "Computational experience
with variants of the Balas algorithm applied to the selection
of R&D projects" Management Science 13(9) (1967) 736-750.
The problem to be solved is:
Max sum{j=1,...,n} p(j)x(j)
st sum{j=1,...,n} r(i,j)x(j) <= b(i) i=1,...,m
x(j)=0 or 1
The format of this data file is:
number of test problems (K)
then for each test problem k (k=1,...,K) in turn:
number of variables (n), number of constraints (m), optimal
solution value (zero if unavailable)
the coefficients p(j); j=1,...,n
for each constraint i (i=1,...,m): the coefficients r(i,j); j=1,...,n
the constraint right-hand sides b(i); i=1,...,m
The second data file is mknap2.
This data file contains 48 test problems taken
from the literature. The format of these problems
is described within the file.
The remaining data files are the problems solved in P.C.Chu and
J.E.Beasley "A genetic algorithm for the multidimensional knapsack
problem", Journal of Heuristics, vol. 4, 1998, pp63-86.
These data files are mknapcb1, mknapcb2, ..., mknapcb9
The format of these data files is the same as the format of mknap1
These data files each contain 30 test problems, the first ten problems
have a tightness ratio of 0.25, the second ten problems have a tightness
ratio of 0.50 and the last ten problems have a tightness ratio of 0.75 (see
the above paper).
The best feasible solution values found and the value of the LP
relaxation for these problems are given in the file mkcbres
The largest file is mknapcb9 of size 2000Kb (approximately)
The entire set of files are of size 5400KB (approximately).

Click here
to access these files