Example #1
0
        /// <summary>
        /// c) Update clustering by calculating the distance between the chromosome genes and the mean vectors for each cluster
        /// </summary>
        /// <param name="numClusters"></param>
        /// <param name="clusterMeanVectors"></param>
        /// <returns></returns>
        public bool updateClustering(int numClusters, double[][] clusterMeanVectors)
        {
            bool go             = true;
            bool hasChanged     = false;
            bool hasZeroMembers = false;

            //Run through all the chromosomes and compare its genes to all the mean vectors. Store new temporary clusterIds
            int[] tempClusterId = new int[chromosomes.Length];

            for (int i = 0; i < chromosomes.Length; i++)
            {
                double[] distances = new double[numClusters];

                //Run through the clusters in order to compare to each mean vector
                for (int j = 0; j < numClusters; j++)
                {
                    distances[j] = Friends.calcDistance(chromosomes[i].GetGenes(), clusterMeanVectors[j]);
                }

                int newClusterId = identifyClusterId(distances);
                tempClusterId[i] = newClusterId;

                if (chromosomes[i].clusterId != newClusterId)
                {
                    hasChanged = true;
                }
            }

            //Check that each new cluster contains at least one chromosome before changing the clusterId property
            int[] tempClusterCounts = new int[numClusters];
            for (int i = 0; i < numClusters; i++)
            {
                tempClusterCounts[i] = 0;
            }

            for (int i = 0; i < chromosomes.Length; i++)
            {
                tempClusterCounts[tempClusterId[i]]++;
            }

            for (int i = 0; i < tempClusterCounts.Length; i++)
            {
                if (tempClusterCounts[i] == 0)
                {
                    hasZeroMembers = true;
                }
            }

            //If no cluster has zero elements then update the chromosome clusterId property
            if (!hasZeroMembers)
            {
                for (int i = 0; i < chromosomes.Length; i++)
                {
                    chromosomes[i].clusterId = tempClusterId[i];
                }
            }

            //Check whether the cluster loop shall continue or not
            if (!hasChanged || hasZeroMembers)
            {
                go = false;
            }

            return(go);
        }