public void TravellingSalesman_Smoke_Test()
{
var graph = new WeightedDiGraph <int, int>();
graph.AddVertex(0);
graph.AddVertex(1);
graph.AddVertex(2);
graph.AddVertex(3);
graph.AddEdge(0, 1, 1);
graph.AddEdge(0, 2, 15);
graph.AddEdge(0, 3, 6);
graph.AddEdge(1, 0, 2);
graph.AddEdge(1, 2, 7);
graph.AddEdge(1, 3, 3);
graph.AddEdge(2, 0, 9);
graph.AddEdge(2, 1, 6);
graph.AddEdge(2, 3, 12);
graph.AddEdge(3, 0, 10);
graph.AddEdge(3, 1, 4);
graph.AddEdge(3, 2, 8);
Assert.AreEqual(21, TravellingSalesman.GetMinWeight(graph));
}
public void ThreeCitiesInATriangle_CorrectlyCalculatesDistances(params double[][] cityLocations)
{
var tsp = new TravellingSalesman("Test Triangle", cityLocations,
DecisionVector.CreateFromArray(DecisionSpace.CreateForUniformIntArray(4, 0, 2), new[] { 0, 1, 2, 0 }));
Assert.Equal(12.0, tsp.Evaluate(tsp.GetGlobalOptimum()).ElementAt(0));
}
public TravellingSalesmanSolver()
{
Problem = new TravellingSalesman();
population = new Population();
population.NumberOfIndividuals = 100;
population.NumberOfObjects = 100;
}
public void TravellingSalesman_AdjacencyMatrixGraph_Smoke_Test()
{
var graph = new Advanced.Algorithms.DataStructures.Graph.AdjacencyMatrix.WeightedDiGraph <int, int>();
graph.AddVertex(0);
graph.AddVertex(1);
graph.AddVertex(2);
graph.AddVertex(3);
graph.AddEdge(0, 1, 1);
graph.AddEdge(0, 2, 15);
graph.AddEdge(0, 3, 6);
graph.AddEdge(1, 0, 2);
graph.AddEdge(1, 2, 7);
graph.AddEdge(1, 3, 3);
graph.AddEdge(2, 0, 9);
graph.AddEdge(2, 1, 6);
graph.AddEdge(2, 3, 12);
graph.AddEdge(3, 0, 10);
graph.AddEdge(3, 1, 4);
graph.AddEdge(3, 2, 8);
var tsp = new TravellingSalesman <int, int>();
Assert.AreEqual(21, tsp.FindMinWeight(graph, new TSPShortestPathOperators()));
}
public void ConstructedFromFile_LoadsCorrectly()
{
var problemFilePath = Path.Combine(Directory.GetCurrentDirectory(),
"SingleObjective", "Discrete", "Resources", "ulysses16.tsp");
var tsp = TravellingSalesman.CreateFromFile(problemFilePath);
Assert.Equal(17, tsp.GetGlobalOptimum().Count);
}
public void Init(Random gen)
{
this.gen = gen;
problem = new TravellingSalesman();
problem.LoadTownsFromFile(DataDir.Towns);
solver = new RandomOptimization <List <Town> >(gen);
solver.ProblemSpace = problem.Towns;
solver.CycleLimit = 1000;
solver.Dice = 3;
solver.Max = 300;
solver.GenerateRandomStart = (towns) =>
{
var route = new List <Town>();
foreach (var town in solver.ProblemSpace)
{
var index = gen.Next(0, route.Count);
route.Insert(index, town);
}
return(route);
};
solver.TakeRandomStepWithinRange = (route, epsilon) =>
{
var alternativeRoute = new List <Town>(route);
// take a random city, put it next to a close one
var choice = alternativeRoute[gen.Next(0, alternativeRoute.Count)];
alternativeRoute.Remove(choice);
var inRange = route.Where(x => x.Distance(choice) <= epsilon).ToList();
inRange.Remove(choice);
var index = alternativeRoute.IndexOf(inRange.First());
alternativeRoute.Insert(index, choice);
return(alternativeRoute);
};
double acceptableLength = 10;
solver.StopCondition = (route) =>
{
return(problem.Objective(route) < acceptableLength);
};
solver.Fitness = (route) =>
{
return(problem.Objective(route));
};
}
public void GivenGraph_WhenGetCheapestPathIsInvoked_NullIsReturned(int graphNumber, string expectedPath, int expectedWeight)
{
// Arrange
var graph = GetGraph(graphNumber);
// Act
var result = TravellingSalesman.GetCheapestPathThroughAllPoints(graph);
// Assert
Assert.Equal(expectedPath, result.Path);
Assert.Equal(expectedWeight, result.Weight);
}
public float SolveTravelingSalesman()
{
var tsp = new TravellingSalesman();
var pointsCount = _ys.Length;
Vector2[] points = new Vector2[pointsCount];
for (int i = 0; i < pointsCount; i++)
{
points[i] = new Vector2((float)_xs[i], (float)_ys[i]);
}
var(pathlength, optimalPath) = tsp.GetTourPathLengthToLastNode(points);
return(pathlength);
}
static void Main(string[] args)
{
Console.WriteLine("Travelling salesman.");
var graph = new Dictionary <string, Dictionary <string, int> >();
AddCity(graph);
var stopwatch = new Stopwatch();
for (var i = 1; i <= 10; i++)
{
AddCity(graph);
stopwatch.Restart();
var result = TravellingSalesman.GetCheapestPathThroughAllPoints(graph);
stopwatch.Stop();
Console.WriteLine($"Result with {graph.Count} cities: {result}. Time taken: {stopwatch.ElapsedMilliseconds}");
}
Console.ReadLine();
}
public void InvalidRoutes_ThrowError()
{
var correctDs = DecisionSpace.CreateForUniformIntArray(3, 0, 1);
var tsp = new TravellingSalesman("A Tale of Two Cities", new List <double[]>()
{
new[] { 0.0, 0 }, new[] { 1.0, 0 }
},
DecisionVector.CreateFromArray(DecisionSpace.CreateForUniformIntArray(3, 0, 2), new[] { 0, 1, 0 }));
// Empty route
Assert.Throws <ArgumentOutOfRangeException>(() => tsp.Evaluate(DecisionVector.CreateForEmpty()));
// Route that is too long with location (2) that doesn't exist
Assert.Throws <ArgumentOutOfRangeException>(() => tsp.Evaluate(
DecisionVector.CreateFromArray(DecisionSpace.CreateForUniformIntArray(4, 0, 2),
new[] { 0, 2, 1, 0 })));
// Route with location (2) that doesn't exist
Assert.Throws <ArgumentOutOfRangeException>(() => tsp.Evaluate(
DecisionVector.CreateFromArray(correctDs,
new[] { 0, 2, 0 })));
}
