public SASolution(SASolution ts, Node a, int routeIndex)
{
rutas = new List <List <Node> >();
foreach (List <Node> lst in ts.rutas)
{
rutas.Add(new List <Node>());
foreach (Node n in lst)
{
rutas[rutas.Count - 1].Add(n);
}
}
depot = ts.depot;
fitness = ts.fitness;
capacidad = ts.capacidad;
feasible = ts.feasible;
int indexRouteNode = GetIdRuta(a);
rutas[indexRouteNode].Remove(a);
rutas[routeIndex].Add(a);
ReordenarNodosRutasMinimizandoCapacidad();
ReordenarNodosRutasMinimizandoDistancia();
}
public Solution RunSA(double alpha, double temperature, double epsilon)
{
int iteration = -1;
//the probability
double proba;
//double alpha = 0.9999;
//double temperature = 400.0;
//double epsilon = 0.0000000001;
double delta;
List <double> lstMinFitness = new List <double>();
int numRutas = Filecvrp.NumRutas;
List <Node> lstNodes = Filecvrp.LstNodes;
Node depot = Filecvrp.LstNodes.Where(e => e.Id == Filecvrp.IdNodeDepot).First();
SASolution currentSolutionSA = new SASolution(numRutas, lstNodes, depot, Filecvrp.Capacity);
currentSolutionSA.CalculateFitness();
double distance = currentSolutionSA.Fitness;
Random r = new Random();
//while the temperature did not reach epsilon
while (temperature > epsilon)
{
iteration++;
//get the next random permutation of distances
int selectedNode = r.Next(0, lstNodes.Count);
while (depot.Id == lstNodes[selectedNode].Id)
{
selectedNode = r.Next(0, lstNodes.Count);
}
Node n = lstNodes[selectedNode];
int routeindex = r.Next(0, numRutas);
SASolution nextSolutionSA = new SASolution(currentSolutionSA, n, routeindex);
nextSolutionSA.CalculateFitness();
//compute the distance of the new permuted configuration
delta = nextSolutionSA.Fitness - distance;
//if the new distance is better accept it and assign it
if (delta < 0 && nextSolutionSA.Feasible)
{
currentSolutionSA = nextSolutionSA;
distance = delta + distance;
}
else
{
proba = r.Next();
//if the new distance is worse accept
//it but with a probability level
//if the probability is less than
//E to the power -delta/temperature.
//otherwise the old value is kept
if (proba < Math.Exp(-delta / temperature))
{
currentSolutionSA = nextSolutionSA;
distance = delta + distance;
}
}
//cooling process on every iteration
temperature *= alpha;
//lstMinFitness.Add(currentSolutionSA.Fitness);
}
distance = currentSolutionSA.Fitness;
Solution s = new Solution();
s.LstMinFitness = lstMinFitness;
s.BestRutas = currentSolutionSA.Rutas;
s.FitnessBestRutas = currentSolutionSA.Fitness;
return(s);
}
