1 简介
Mirjalili 等人提出了一种新的群体智能算法———灰狼优化算法(GWO),并通过多个基准测试函数进行测试,从结果上验证了该算法的可行性,通过对比,GWO 算法已被证明在算法对函数求解精度和稳定性上要明显优于 PSO、DE 和 GSA 算 法。
生物在自然界严酷环境下,即使并不具有人类的高智能,但在相同的目标,即食物的激励下,通过不断地适应与集体合作都表现出了令人惊叹的群体智能。文献[6]基于狼群严密的组织系统及其精妙的协作捕猎方式,提出了一种新的群体智能算法———灰狼优化算法。
2 部分代码
%% Non Sorted Grey Wolf Algorithm (NSGWO)
clc
clear all
D = 30; % Number of decision variables
M = 2; % Number of objective functions
K=M+D;
LB = ones(1, D).*0; % LB - A vector of decimal values which indicate the minimum value for each decision variable.
UB = ones(1, D).*1; % UB - Vector of maximum possible values for decision variables.
Max_iteration = 100; % Set the maximum number of generation (GEN)
SearchAgents_no = 100; % Set the population size (Search Agent)
ishow = 10;
%% Initialize the population
% Population is initialized with random values which are within the
% specified range. Each chromosome consists of the decision variables. Also
% the value of the objective functions, rank and crowding distance
% information is also added to the chromosome vector but only the elements
% of the vector which has the decision variables are operated upon to
% perform the genetic operations like corssover and mutation.
chromosome = initialize_variables(SearchAgents_no, M, D, LB, UB);
%% Sort the initialized population
% Sort the population using non-domination-sort. This returns two columns
% for each individual which are the rank and the crowding distance
% corresponding to their position in the front they belong. At this stage
% the rank and the crowding distance for each chromosome is added to the
% chromosome vector for easy of computation.
intermediate_chromosome = non_domination_sort_mod(chromosome, M, D);
%% Perform Selection
% Once the intermediate population is sorted only the best solution is
% selected based on it rank and crowding distance. Each front is filled in
% ascending order until the addition of population size is reached. The
% last front is included in the population based on the individuals with
% least crowding distance
% Select NP fittest solutions using non dominated and crowding distance
% sorting and store in population
Population = replace_chromosome(intermediate_chromosome, M,D,SearchAgents_no);
%% Start the evolution process
% The following are performed in each generation
% * Select the parents which are fit for reproduction
% * Perfrom crossover and Mutation operator on the selected parents
% * Perform Selection from the parents and the offsprings
% * Replace the unfit individuals with the fit individuals to maintain a
% constant population size.
Pareto = NSGWO(D,M,LB,UB,Population,SearchAgents_no,Max_iteration,ishow);
save Pareto.txt Pareto -ascii; % save data for future use
%% Plot data
if M == 2
plot_data2(M,D,Pareto)
elseif M == 3
plot_data_TCQ(M,D,Pareto);
end
3 仿真结果
4 参考文献
[1]孟安波, and 林艺城. "一种基于多目标的改进灰狼优化算法.", CN107067121A. 2017.