粒子群pso算法

% 粒子群算法
% 标准函数测试
% 2005年10月

function PSO_test（）
 
    clear;

    % select an optimization problem
    NP_problem = 1;
    switch NP_problem
        case 0                                                              % F6
            % Shaffer‘ 2s F6 -100~100在x=0和y=0的条件下有fitness_max=1
            uplimit = 10;
            dnlimit = -10;
        case 1
            % Ras 函数，在x=0和y=0的条件下有最小值ras=0
            uplimit = 1;
            dnlimit = -1;
        case 2
            % Rosenbrock 函数，在x=1和y=1的条件下有最小值ros=0
            uplimit = 2;                              % uplimit of each bit
            dnlimit = -2;                             % dnlimit of each bit
    end

    % ---------- Initilization ----------
    num_state = 2;                              % number of vectors
    popsize = 30;                                % number of particles
    max_gen = 400;                              % generation of evolution
    max_v = 1;                                  % maximum velocity
    c1 = 2;                                     % self learning factor
    c2 = 0;                                     % social learning factor
    w_max = 0.9;                                % The maximum velocity coefficient
    w_min = 0.4;                                % The minimum velocity coefficient    
    pbest = zeros（popsize1）;                   % the best fitness among all selves
    gbest = 0;                                  % the best fitness among all 
    pid = [];                                   % the particle corresponding to pbest
    pgd = [];                                   % the particle corresponding to gbest
%    rand（‘seed‘1111）;                          % remember the random seed
    p = rand（popsizenum_state）*（uplimit-dnlimit）+dnlimit;            % particle positions
%    rand（‘seed‘2222）;                          % remember the random seed
    v = rand（popsizenum_state）;                % particle velocities
            
    % start the inherit operation
    t0 = clock;

    % ---------- PSO Calculation Comparison and