中文说明：这是一个粒子群算法（PSO）用于特征选择的matlab函数，用户可以自由选择目标函数优化方向、种群大小、迭代次数等等。
English Description：
This is a matlab function of particle swarm optimization (PSO) for feature selection. Users can freely choose the optimization direction of the objective function, the size of the population, the number of iterations and so on.