object, nObj: An object of class 'nsga2', usually resulting from a call to function nsga2. Fitness Function Objective Numbers
Returns
A vector with the crowding-distance between individuals of a population.
Details
The crowded-comparison operator guides the selection process at the various stages of the algorithm toward a uniformly spread-out Pareto-optimal front
References
K. Deb, A. Pratap, S. Agarwal and T. Meyarivan, 'A fast and elitist multiobjective genetic algorithm: NSGA-II,' in IEEE Transactions on Evolutionary Computation, vol. 6, no. 2, pp. 182-197, April 2002, doi: 10.1109/4235.996017.