Discrete location problems Benchmark library
Competitive facility
location problem
Test instances. Class A For this class of instances the set of candidate sites and the set of clients are equal to the set of vertices of some random graph. Instances are generated as follows: m numbered points are randomly thrown on the unit square. Coordinates of each point are realizations of the uniformly distributed in the [0,1] random variable.The probability of two points to be connected with edge is decreasing as like as exp(–d 2), where d is euclidean distance between the points. The length of the new edge is equal to d. The distance between connected components are assumed to be inifinite.
For each pair of vertices i, j the value rij is assumed to be equal to the number of vertices, which are closer (in the sence of graph distances) to vertex j than vertex i or which are located at the same distance from j and their number is smaller than i. For given j values rij are pairwise different integer numbers from 0 to m – 1.
fi = 40;
gi = random integer from 25 to 35;
pij = bj, if rij < Rj and 0 otherwise, where bj = random integer from 10 to 20, Rj = random integer from 1 to m.
Input data format:
each string contains only one value;
parameters are given in the following order: m, n, (rij) line by line[1], pij line by line, fi , gi.
[1] for example, elements of 2x2-matrix A will be ordered as follows: a11, a12, a21, a22.
Instances' codes have the following meaning: a20-01 — instance from class A, m = n = 20, unique number 01.
Instance code
UB
VLrecord
xrecord
315
155
x*
270
138
x*
207
159
x*
239
81
x*
216
136
x*
236
117
x*
246
115
x*
206
92
x*
263
176
x*
241
143
x*
147
89
x*
259
144
x*
224
91
x*
218
96
x*
218
107
x*
231
93
x*
259
98
x*
295
164
x*
229
112
x*
238
123
x*