levy.zip_MATLAB实现_levy_levy 分布_levy分布_levy分布 matlab

function [z] = levy(n,m,beta) % This function implements Levy's flight. % For more information see %'Multiobjective cuckoo search for design optimization Xin-She Yang, Suash Deb'. % Coded by Hemanth Manjunatha on Nov 13 2015. % Input parameters % n -> Number of steps % m -> Number of Dimensions % beta -> Power law index % Note: 1 < beta < 2 % Output % z -> 'n' levy steps in 'm' dimension num = gamma(1+beta)*sin(pi*beta/2); % used for Numerator den = gamma((1+beta)/2)*beta*2^((beta-1)/2); % used for Denominator sigma_u = (num/den)^(1/beta);% Standard deviation u = random('Normal',0,sigma_u^2,n,m); v = random('Normal',0,1,n,m); z = u./(abs(v).^(1/beta)); end