# 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.

## Euclidean Steiner problem

There are currently 15 data files.
These data files are the test problems solved in J.E.Beasley
"A heuristic for Euclidean and rectilinear Steiner problems",
European Journal of Operational Research 58 (1992) 284-292.
These data files include the 46 test problems from J.Soukup
and W.F.Chow "Set of test problems for the minimum length
connection networks" ACM/SIGMAP Newsletter 15 (1973) 48-51.
The following table gives the relationship between test problems
and the appropriate file.
Number of points (n) File
10 estein10
20 estein20
30 estein30
40 estein40
50 estein50
60 estein60
70 estein70
80 estein80
90 estein90
100 estein100
250 estein250
500 estein500
1000 estein1000
10000 estein10000
The Soukup and Chow test problems are in data file estein1.
The format of these data files is:
number of test problems (m)
for each test problem i (i=1,...,m) in turn:
number of points (n)
for each point j (j=1,...,n): x-coordinate, y-coordinate
Optimal solution information for files estein1, estein10, ...,estein100
can be found in the files estein1opt, estein10opt, ...,estein100opt.
These files were contributed by Martin Zachariasen of the University
of Copenhagen (email martinz@diku.dk) and were found using the algorithm
described in "Large Euclidean Steiner minimal trees in an hour" by
P. Winter and M. Zachariasen, available here
The format of these files is:
number of test problems (m)
for each test problem i (i=1,...,m) in turn:
optimal steiner solution value
minimal spanning tree solution value
number of Steiner points (S)
for each Steiner point s (s=1,...,S): x-coordinate, y-coordinate
The largest file is estein1000 of size 350Kb (approximately).
The entire set of files is of size 1100Kb (approximately).

Click here
to access these files