COIN-OR::LEMON - Graph Library

source: lemon/test/tsp_test.cc @ 1303:1ba759c76810

Last change on this file since 1303:1ba759c76810 was 1303:1ba759c76810, checked in by Alpar Juttner <alpar@…>, 6 years ago

Bugfix in tsp_test (#476)

File size: 9.3 KB
Line 
1/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library.
4 *
5 * Copyright (C) 2003-2013
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 *
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
12 *
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
15 * purpose.
16 *
17 */
18
19#include <iostream>
20
21#include <lemon/full_graph.h>
22#include <lemon/math.h>
23#include <lemon/maps.h>
24#include <lemon/random.h>
25#include <lemon/dim2.h>
26
27#include <lemon/nearest_neighbor_tsp.h>
28#include <lemon/greedy_tsp.h>
29#include <lemon/insertion_tsp.h>
30#include <lemon/christofides_tsp.h>
31#include <lemon/opt2_tsp.h>
32
33#include "test_tools.h"
34
35using namespace lemon;
36
37// // Tests checkMetricCost() function
38// void metricCostTest() {
39//   GRAPH_TYPEDEFS(FullGraph);
40//   FullGraph g(10);
41//   check(checkMetricCost(g, constMap<Edge>(0)), "Wrong checkMetricCost()");
42//   check(checkMetricCost(g, constMap<Edge>(1)), "Wrong checkMetricCost()");
43//   check(!checkMetricCost(g, constMap<Edge>(-1)), "Wrong checkMetricCost()");
44//
45//   FullGraph::EdgeMap<float> cost(g);
46//   for (NodeIt u(g); u != INVALID; ++u) {
47//     for (NodeIt v(g); v != INVALID; ++v) {
48//       if (u == v) continue;
49//       float x1 = g.id(u), x2 = g.id(v);
50//       float y1 = x1 * x1, y2 = x2 * x2;
51//       cost[g.edge(u, v)] = std::sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1));
52//     }
53//   }
54//   check(checkMetricCost(g, cost), "Wrong checkMetricCost()");
55//   float eps = Tolerance<float>::defaultEpsilon();
56//   cost[g.edge(g(0), g(9))] =
57//     cost[g.edge(g(0), g(8))] + cost[g.edge(g(8), g(9))] + eps * 2;
58//   check(!checkMetricCost(g, cost), "Wrong checkMetricCost()");
59//   check(checkMetricCost(g, cost, Tolerance<float>(eps * 4)),
60//     "Wrong checkMetricCost()");
61// }
62
63// Checks tour validity
64template <typename Container>
65bool checkTour(const FullGraph &gr, const Container &p) {
66  FullGraph::NodeMap<bool> used(gr, false);
67
68  int node_cnt = 0;
69  for (typename Container::const_iterator it = p.begin(); it != p.end(); ++it)
70    {
71      FullGraph::Node node = *it;
72      if (used[node]) return false;
73      used[node] = true;
74      ++node_cnt;
75    }
76
77  return (node_cnt == gr.nodeNum());
78}
79
80// Checks tour validity
81bool checkTourPath(const FullGraph &gr, const Path<FullGraph> &p) {
82  FullGraph::NodeMap<bool> used(gr, false);
83
84  if (!checkPath(gr, p)) return false;
85  if (gr.nodeNum() <= 1 && p.length() != 0) return false;
86  if (gr.nodeNum() > 1 && p.length() != gr.nodeNum()) return false;
87
88  for (int i = 0; i < p.length(); ++i) {
89    if (used[gr.target(p.nth(i))]) return false;
90    used[gr.target(p.nth(i))] = true;
91  }
92  return true;
93}
94
95// Checks tour cost
96template <typename CostMap>
97bool checkCost(const FullGraph &gr, const std::vector<FullGraph::Node> &p,
98               const CostMap &cost, typename CostMap::Value total)
99{
100  typedef typename CostMap::Value Cost;
101
102  Cost s = 0;
103  for (int i = 0; i < int(p.size()) - 1; ++i)
104    s += cost[gr.edge(p[i], p[i+1])];
105  if (int(p.size()) >= 2)
106    s += cost[gr.edge(p.back(), p.front())];
107
108  return !Tolerance<Cost>().different(s, total);
109}
110
111// Checks tour cost
112template <typename CostMap>
113bool checkCost(const FullGraph &, const Path<FullGraph> &p,
114               const CostMap &cost, typename CostMap::Value total)
115{
116  typedef typename CostMap::Value Cost;
117
118  Cost s = 0;
119  for (int i = 0; i < p.length(); ++i)
120    s += cost[p.nth(i)];
121
122  return !Tolerance<Cost>().different(s, total);
123}
124
125// Tests a TSP algorithm on small graphs
126template <typename TSP>
127void tspTestSmall(const std::string &alg_name) {
128  GRAPH_TYPEDEFS(FullGraph);
129
130  for (int n = 0; n <= 5; ++n) {
131    FullGraph g(n);
132    unsigned nsize = n;
133    int esize = n <= 1 ? 0 : n;
134
135    ConstMap<Edge, int> cost_map(1);
136    TSP alg(g, cost_map);
137
138    check(alg.run() == esize, alg_name + ": Wrong total cost");
139    check(alg.tourCost() == esize, alg_name + ": Wrong total cost");
140
141    std::list<Node> list1(nsize), list2;
142    std::vector<Node> vec1(nsize), vec2;
143    alg.tourNodes(list1.begin());
144    alg.tourNodes(vec1.begin());
145    alg.tourNodes(std::front_inserter(list2));
146    alg.tourNodes(std::back_inserter(vec2));
147    check(checkTour(g, alg.tourNodes()), alg_name + ": Wrong node sequence");
148    check(checkTour(g, list1), alg_name + ": Wrong node sequence");
149    check(checkTour(g, vec1), alg_name + ": Wrong node sequence");
150    check(checkTour(g, list2), alg_name + ": Wrong node sequence");
151    check(checkTour(g, vec2), alg_name + ": Wrong node sequence");
152    check(checkCost(g, vec1, constMap<Edge, int>(1), esize),
153      alg_name + ": Wrong tour cost");
154
155    SimplePath<FullGraph> path;
156    alg.tour(path);
157    check(path.length() == esize, alg_name + ": Wrong tour");
158    check(checkTourPath(g, path), alg_name + ": Wrong tour");
159    check(checkCost(g, path, constMap<Edge, int>(1), esize),
160      alg_name + ": Wrong tour cost");
161  }
162}
163
164// Tests a TSP algorithm on random graphs
165template <typename TSP>
166void tspTestRandom(const std::string &alg_name) {
167  GRAPH_TYPEDEFS(FullGraph);
168
169  FullGraph g(20);
170  FullGraph::NodeMap<dim2::Point<double> > pos(g);
171  DoubleEdgeMap cost(g);
172
173  TSP alg(g, cost);
174  Opt2Tsp<DoubleEdgeMap > opt2(g, cost);
175
176  for (int i = 1; i <= 3; i++) {
177    for (NodeIt u(g); u != INVALID; ++u) {
178      pos[u] = dim2::Point<double>(rnd(), rnd());
179    }
180    for (NodeIt u(g); u != INVALID; ++u) {
181      for (NodeIt v(g); v != INVALID; ++v) {
182        if (u == v) continue;
183        cost[g.edge(u, v)] = (pos[u] - pos[v]).normSquare();
184      }
185    }
186
187    check(alg.run() > 0, alg_name + ": Wrong total cost");
188
189    std::vector<Node> vec;
190    alg.tourNodes(std::back_inserter(vec));
191    check(checkTour(g, vec), alg_name + ": Wrong node sequence");
192    check(checkCost(g, vec, cost, alg.tourCost()),
193      alg_name + ": Wrong tour cost");
194
195    SimplePath<FullGraph> path;
196    alg.tour(path);
197    check(checkTourPath(g, path), alg_name + ": Wrong tour");
198    check(checkCost(g, path, cost, alg.tourCost()),
199      alg_name + ": Wrong tour cost");
200
201    check(!Tolerance<double>().less(alg.tourCost(), opt2.run(alg.tourNodes())),
202      "2-opt improvement: Wrong total cost");
203    check(checkTour(g, opt2.tourNodes()),
204      "2-opt improvement: Wrong node sequence");
205    check(checkCost(g, opt2.tourNodes(), cost, opt2.tourCost()),
206      "2-opt improvement: Wrong tour cost");
207
208    check(!Tolerance<double>().less(alg.tourCost(), opt2.run(path)),
209      "2-opt improvement: Wrong total cost");
210    check(checkTour(g, opt2.tourNodes()),
211      "2-opt improvement: Wrong node sequence");
212    check(checkCost(g, opt2.tourNodes(), cost, opt2.tourCost()),
213      "2-opt improvement: Wrong tour cost");
214  }
215}
216
217// Algorithm class for Nearest Insertion
218template <typename CM>
219class NearestInsertionTsp : public InsertionTsp<CM> {
220public:
221  NearestInsertionTsp(const FullGraph &gr, const CM &cost)
222    : InsertionTsp<CM>(gr, cost) {}
223  typename CM::Value run() {
224    return InsertionTsp<CM>::run(InsertionTsp<CM>::NEAREST);
225  }
226};
227
228// Algorithm class for Farthest Insertion
229template <typename CM>
230class FarthestInsertionTsp : public InsertionTsp<CM> {
231public:
232  FarthestInsertionTsp(const FullGraph &gr, const CM &cost)
233    : InsertionTsp<CM>(gr, cost) {}
234  typename CM::Value run() {
235    return InsertionTsp<CM>::run(InsertionTsp<CM>::FARTHEST);
236  }
237};
238
239// Algorithm class for Cheapest Insertion
240template <typename CM>
241class CheapestInsertionTsp : public InsertionTsp<CM> {
242public:
243  CheapestInsertionTsp(const FullGraph &gr, const CM &cost)
244    : InsertionTsp<CM>(gr, cost) {}
245  typename CM::Value run() {
246    return InsertionTsp<CM>::run(InsertionTsp<CM>::CHEAPEST);
247  }
248};
249
250// Algorithm class for Random Insertion
251template <typename CM>
252class RandomInsertionTsp : public InsertionTsp<CM> {
253public:
254  RandomInsertionTsp(const FullGraph &gr, const CM &cost)
255    : InsertionTsp<CM>(gr, cost) {}
256  typename CM::Value run() {
257    return InsertionTsp<CM>::run(InsertionTsp<CM>::RANDOM);
258  }
259};
260
261int main() {
262  GRAPH_TYPEDEFS(FullGraph);
263
264  // metricCostTest();
265
266  tspTestSmall<NearestNeighborTsp<ConstMap<Edge, int> > >("Nearest Neighbor");
267  tspTestSmall<GreedyTsp<ConstMap<Edge, int> > >("Greedy");
268  tspTestSmall<NearestInsertionTsp<ConstMap<Edge, int> > >("Nearest Insertion");
269  tspTestSmall<FarthestInsertionTsp<ConstMap<Edge, int> > >
270    ("Farthest Insertion");
271  tspTestSmall<CheapestInsertionTsp<ConstMap<Edge, int> > >
272    ("Cheapest Insertion");
273  tspTestSmall<RandomInsertionTsp<ConstMap<Edge, int> > >("Random Insertion");
274  tspTestSmall<ChristofidesTsp<ConstMap<Edge, int> > >("Christofides");
275  tspTestSmall<Opt2Tsp<ConstMap<Edge, int> > >("2-opt");
276
277  tspTestRandom<NearestNeighborTsp<DoubleEdgeMap > >("Nearest Neighbor");
278  tspTestRandom<GreedyTsp<DoubleEdgeMap > >("Greedy");
279  tspTestRandom<NearestInsertionTsp<DoubleEdgeMap > >("Nearest Insertion");
280  tspTestRandom<FarthestInsertionTsp<DoubleEdgeMap > >("Farthest Insertion");
281  tspTestRandom<CheapestInsertionTsp<DoubleEdgeMap > >("Cheapest Insertion");
282  tspTestRandom<RandomInsertionTsp<DoubleEdgeMap > >("Random Insertion");
283  tspTestRandom<ChristofidesTsp<DoubleEdgeMap > >("Christofides");
284  tspTestRandom<Opt2Tsp<DoubleEdgeMap > >("2-opt");
285
286  return 0;
287}
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