public void Merge(Neighborhood other)
{
// Add all the fusions from the other neighborhood into this
// neighborhood
foreach (Fusion fusion in other)
{
Add(fusion);
}
// Make sure to also update the best configuration if the best configuration
// from the other neighborhood is better than this one
if (other.ConfigurationBest != null &&
(d_best == null || other.ConfigurationBest.Fitness > d_best.Fitness))
{
d_best = (Particle)other.ConfigurationBest.Clone();
}
}
public override void InitializePopulation()
{
base.InitializePopulation();
d_mutationProbability.Parse(Configuration.MutationProbability);
d_socialMutationProbability.Parse(Configuration.SocialMutationProbability);
d_cognitiveMutationProbability.Parse(Configuration.CognitiveMutationProbability);
if (Configuration.MinNeighborhoods <= 0)
{
Configuration.MinNeighborhoods = 1;
}
d_subswarmBests = new Dictionary <uint, Particle>();
int idx = 0;
if (Configuration.FusedParticles <= 0)
{
throw new Exception("Number of fused particles must be larger than 0");
}
// Do the particle fusion
Neighborhood neighborhood = new Neighborhood();
/* Calculate the number of fusion sets in each neighborhood to fullfil
* the initial number of neighborhoods constraint:
*
* n = Ceil(PopulationSize / FusionSize) / InitialNeighborhoods
* */
double fusionPerNeighborhood;
if (Configuration.InitialNeighborhoods <= 0)
{
// Maximum number of neighborhoods
fusionPerNeighborhood = 2;
}
else
{
fusionPerNeighborhood = System.Math.Ceiling(Population.Count / (double)Configuration.FusedParticles) / Configuration.InitialNeighborhoods;
}
if (fusionPerNeighborhood < 1)
{
fusionPerNeighborhood = 1;
}
double nextFusion = fusionPerNeighborhood;
while (idx < Population.Count)
{
List <Solution> solutions = Population.GetRange(idx, System.Math.Min(Configuration.FusedParticles, Population.Count - idx));
List <Particle> particles = new List <Particle>();
idx += Configuration.FusedParticles;
foreach (Solution solution in solutions)
{
particles.Add((Particle)solution);
}
// Create new fusion set for the particles
Fusion fus = new Fusion(particles, State);
// Initialize will intialize the subswarm configuration of the fusion set
fus.Initialize();
// Add the fusion set to the neighborhood
neighborhood.Add(fus);
if (neighborhood.Count >= nextFusion)
{
nextFusion += fusionPerNeighborhood - neighborhood.Count;
d_neighborhoods.Add(neighborhood);
neighborhood = new Neighborhood();
}
}
if (neighborhood.Count != 0)
{
d_neighborhoods.Add(neighborhood);
}
if (Configuration.MergeInterval == 0)
{
/* Calculate the merge interval based on the number of neighborhoods,
* number of particles and number of iterations.
*
* Number of merges 'nm':
* ------------------------------------------------------
* 2^n = numNeighborhoods
* n = log(numNeighborhoods - minNeighborhoods) / log(2)
* interval = maxIterations / (n + 1)
*/
double num = System.Math.Ceiling(System.Math.Log(d_neighborhoods.Count / Configuration.MinNeighborhoods) / System.Math.Log(2));
Configuration.MergeInterval = Configuration.MaxIterations / (double)(num + 1);
}
d_nextMerge = Configuration.MergeInterval;
}
