public void recomputeCentroidAndStdDev(double[][] data, int numObs, int numFeatures) {
			double[] newCentroid = new double[numFeatures];
			for(int i = 0; i < members.size(); i++) {
				for(int j = 0; j < numFeatures; j++) {
					newCentroid[j] += data[members.get(i)][j];
				}
			}
			for(int j = 0; j < numFeatures; j++) {
				newCentroid[j] = newCentroid[j]/members.size();
			}
			centroid = newCentroid;
			
			double[] clusterStdDev = new double[numFeatures];
			for(int i = 0; i < members.size(); i++) {
				for(int j = 0; j < numFeatures; j++) {
					clusterStdDev[j] += Math.pow(data[members.get(i)][j] - centroid[j], 2);
				}
			}
			for(int j = 0; j < numFeatures; j++) {
				clusterStdDev[j] =  Math.sqrt(clusterStdDev[j]/members.size());
			}
			stdDev = clusterStdDev;
		}