private double[] calculateCognitiveVelocity(int particle, double r1) {
		double[] cognitiveVelocity = new double[position[particle].length];
		for(int k = 0; k < cognitiveVelocity.length; k++){
			cognitiveVelocity[k] = cognitiveConstant * r1 * (personalBest[particle][k] - position[particle][k]);
		}
		return cognitiveVelocity;
	}