Pareto frontier graphic via python

Pareto frontiers are not strictly dominated by any others. An element is dominated if there exists an other element in the set of elements having a better score on one criterion and at least the same score on the others. Here a little example Python Pareto frontier code.

import matplotlib.pyplot as plt

def plot_pareto_frontier(Xs, Ys, maxX=True, maxY=True):
    '''Pareto frontier selection process'''
    sorted_list = sorted([[Xs[i], Ys[i]] for i in range(len(Xs))], reverse=maxY)
    pareto_front = [sorted_list[0]]
    for pair in sorted_list[1:]:
        if maxY:
            if pair[1] >= pareto_front[-1][1]:
                pareto_front.append(pair)
        else:
            if pair[1] <= pareto_front[-1][1]:
                pareto_front.append(pair)
    
    '''Plotting process'''
    plt.scatter(Xs,Ys)
    pf_X = [pair[0] for pair in pareto_front]
    pf_Y = [pair[1] for pair in pareto_front]
    plt.plot(pf_X, pf_Y)
    plt.xlabel("Objective 1")
    plt.ylabel("Objective 2")
    plt.show()

An example Pareto frontier graphic is produced by above python function.

Reference 1. http://code.activestate.com/recipes/578230-pareto-front/