public Dictionary <int, Route> RunACO(Graph graph)
{
pheromoneLookup.InitialisePheremoneOnAllEdges(graph.GraphOfNodes.Count);
antPopulation = InitialiseAntPopulation();
for (int generation = 0; generation < ACOConstants.DEFAULT_ANT_GENERATIONS; generation++)
{
foreach (Ant ant in antPopulation)
{
Route route = ant.WalkRoute(pheromoneLookup, routeEvaluator, graph);
route.RouteCost = routeEvaluator.CalculateCostOfSingleRoute(route.RouteIds, graph);
}
// Seperate loop for pheremones so ants do not converge on a single route immediately
foreach (Ant ant in antPopulation)
{
pheromoneLookup.UpdatePheromoneForSingleRoute(ant.AntRoute.RouteIds);
ant.ClearRoutes();
}
pheromoneLookup.DecayAllPheromones();
List <Route> antRoutes = new List <Route>();
antPopulation.ForEach(ant => antRoutes.Add(ant.AntRoute));
FindBestRouteInGeneration(generation, antRoutes);
}
return(BestRouteInGeneration);
}
private List <Route> InitialisePoplulation(Graph graph)
{
List <Route> tempPopulation = new List <Route>();
for (int index = 0; index < EvolutionaryAlgorithmConstants.POPULATION_SIZE; index++)
{
int[] routeIds = randomRouteGenerator.GenerateSingleRandomRoute(graph.GraphOfNodes.Count);
double routeCost = routeEvaluator.CalculateCostOfSingleRoute(routeIds, graph);
Route currentRoute = new Route(routeIds, routeCost);
Route currentBestRoute = BestRouteInGeneration.ElementAt(0).Value;
if (currentRoute.RouteCost < currentBestRoute.RouteCost)
{
BestRouteInGeneration.Remove(0);
BestRouteInGeneration.Add(0, currentRoute);
}
tempPopulation.Add(currentRoute);
}
return(tempPopulation);
}
public void ConstructGreedyRoute(Graph graph, RouteEvaluator routeEvaluator)
{
int startEndCity = InitialiseFirstCity(graph);
while (CurrentRoute.Count <= graph.GraphOfNodes.Count)
{
CurrentRoute.Add(graph.GetClosestCity(CurrentRoute.Count - 1, VisitedCities));
}
CurrentRoute.Add(startEndCity);
int[] CurrentRouteArray = CurrentRoute.ToArray();
double routeCost = routeEvaluator.CalculateCostOfSingleRoute(CurrentRouteArray, graph);
AntRoute = new Route(CurrentRouteArray, routeCost);
}
private Route FindBestTourInNeighbourhood(List <int[]> routes, Graph graph)
{
int[] bestRoute = new int[routes.ElementAt(0).Length];
double bestCost = 0;
foreach (int[] route in routes)
{
double routeCost = routeEvaluator.CalculateCostOfSingleRoute(route, graph);
if (bestCost == 0 || routeCost < bestCost)
{
bestCost = routeCost;
bestRoute = route;
}
}
return(new Route(bestRoute, bestCost));
}
public KeyValuePair <int[], double> CalculateBestRandomRouteInGivenTime(Graph graph, int timeToExecuteFor)
{
int[] lowestCostRoute = new int[graph.GraphOfNodes.Count + 1];
double currentLowestCostRoute = 0;
int timeToExecuteForInMilliSec = timeToExecuteFor * 1000;
var now = DateTime.Now;
while (DateTime.Now < now.AddMilliseconds(timeToExecuteForInMilliSec))
{
// This is duplicated in menu. Must be a better layout than copy paste
int[] route = randomRouteGenerator.GenerateSingleRandomRoute(graph.GraphOfNodes.Count);
double costOfRoute = routeEvaluator.CalculateCostOfSingleRoute(route, graph);
if (IsLowestCostOfRouteSoFar(currentLowestCostRoute, costOfRoute))
{
lowestCostRoute = route;
currentLowestCostRoute = costOfRoute;
}
}
return(new KeyValuePair <int[], double>(lowestCostRoute, currentLowestCostRoute));
}
