灰狼優化算法——MATLAB


 1 tic % 計時器  2 %% 清空環境變量  3 close all  4 clear  5 clc  6 format compact  7 %% 數據提取  8 % 載入測試數據wine,其中包含的數據為classnumber = 3,wine:178*13的矩陣,wine_labes:178*1的列向量  9 load wine.mat  10 % 選定訓練集和測試集  11 % 將第一類的1-30,第二類的60-95,第三類的131-153做為訓練集  12 train_wine = [wine(1:30,:);wine(60:95,:);wine(131:153,:)];  13 % 相應的訓練集的標簽也要分離出來  14 train_wine_labels = [wine_labels(1:30);wine_labels(60:95);wine_labels(131:153)];  15 % 將第一類的31-59,第二類的96-130,第三類的154-178做為測試集  16 test_wine = [wine(31:59,:);wine(96:130,:);wine(154:178,:)];  17 % 相應的測試集的標簽也要分離出來  18 test_wine_labels = [wine_labels(31:59);wine_labels(96:130);wine_labels(154:178)];  19 %% 數據預處理  20 % 數據預處理,將訓練集和測試集歸一化到[0,1]區間  21 [mtrain,ntrain] = size(train_wine);  22 [mtest,ntest] = size(test_wine);  23 
 24 dataset = [train_wine;test_wine];  25 % mapminmax為MATLAB自帶的歸一化函數  26 [dataset_scale,ps] = mapminmax(dataset',0,1);
 27 dataset_scale = dataset_scale';
 28 
 29 train_wine = dataset_scale(1:mtrain,:);  30 test_wine = dataset_scale( (mtrain+1):(mtrain+mtest),: );  31 %% 利用灰狼算法選擇最佳的SVM參數c和g  32 SearchAgents_no=10; % 狼群數量,Number of search agents  33 Max_iteration=10; % 最大迭代次數,Maximum numbef of iterations  34 dim=2; % 此例需要優化兩個參數c和g,number of your variables  35 lb=[0.01,0.01]; % 參數取值下界  36 ub=[100,100]; % 參數取值上界  37 % v = 5; % SVM Cross Validation參數,默認為5  38 
 39 % initialize alpha, beta, and delta_pos  40 Alpha_pos=zeros(1,dim); % 初始化Alpha狼的位置  41 Alpha_score=inf; % 初始化Alpha狼的目標函數值,change this to -inf for maximization problems  42 
 43 Beta_pos=zeros(1,dim); % 初始化Beta狼的位置  44 Beta_score=inf; % 初始化Beta狼的目標函數值,change this to -inf for maximization problems  45 
 46 Delta_pos=zeros(1,dim); % 初始化Delta狼的位置  47 Delta_score=inf; % 初始化Delta狼的目標函數值,change this to -inf for maximization problems  48 
 49 %Initialize the positions of search agents  50 Positions=initialization(SearchAgents_no,dim,ub,lb);  51 
 52 Convergence_curve=zeros(1,Max_iteration);  53 
 54 l=0; % Loop counter循環計數器  55 
 56 % Main loop主循環  57 while l<Max_iteration  % 對迭代次數循環  58     for i=1:size(Positions,1)  % 遍歷每個狼  59         
 60        % Return back the search agents that go beyond the boundaries of the search space  61        % 若搜索位置超過了搜索空間,需要重新回到搜索空間  62         Flag4ub=Positions(i,:)>ub;  63         Flag4lb=Positions(i,:)<lb;  64         % 若狼的位置在最大值和最小值之間,則位置不需要調整,若超出最大值,最回到最大值邊界;  65         % 若超出最小值,最回答最小值邊界  66         Positions(i,:)=(Positions(i,:).*(~(Flag4ub+Flag4lb)))+ub.*Flag4ub+lb.*Flag4lb; % ~表示取反  67      
 68       % 計算適應度函數值  69        cmd = [' -c ',num2str(Positions(i,1)),' -g ',num2str(Positions(i,2))];  70        model=svmtrain(train_wine_labels,train_wine,cmd); % SVM模型訓練  71        [~,fitness]=svmpredict(test_wine_labels,test_wine,model); % SVM模型預測及其精度  72        fitness=100-fitness(1); % 以錯誤率最小化為目標  73     
 74         % Update Alpha, Beta, and Delta  75         if fitness<Alpha_score % 如果目標函數值小於Alpha狼的目標函數值  76             Alpha_score=fitness; % 則將Alpha狼的目標函數值更新為最優目標函數值,Update alpha  77             Alpha_pos=Positions(i,:); % 同時將Alpha狼的位置更新為最優位置  78  end  79         
 80         if fitness>Alpha_score && fitness<Beta_score % 如果目標函數值介於於Alpha狼和Beta狼的目標函數值之間  81             Beta_score=fitness; % 則將Beta狼的目標函數值更新為最優目標函數值,Update beta  82             Beta_pos=Positions(i,:); % 同時更新Beta狼的位置  83  end  84         
 85         if fitness>Alpha_score && fitness>Beta_score && fitness<Delta_score  % 如果目標函數值介於於Beta狼和Delta狼的目標函數值之間  86             Delta_score=fitness; % 則將Delta狼的目標函數值更新為最優目標函數值,Update delta  87             Delta_pos=Positions(i,:); % 同時更新Delta狼的位置  88  end  89  end  90     
 91     a=2-l*((2)/Max_iteration); % 對每一次迭代,計算相應的a值,a decreases linearly fron 2 to 0
 92     
 93     % Update the Position of search agents including omegas  94     for i=1:size(Positions,1) % 遍歷每個狼  95         for j=1:size(Positions,2) % 遍歷每個維度  96             
 97             % 包圍獵物,位置更新  98             
 99             r1=rand(); % r1 is a random number in [0,1] 100             r2=rand(); % r2 is a random number in [0,1] 101             
102             A1=2*a*r1-a; % 計算系數A,Equation (3.3) 103             C1=2*r2; % 計算系數C,Equation (3.4) 104             
105             % Alpha狼位置更新 106             D_alpha=abs(C1*Alpha_pos(j)-Positions(i,j)); % Equation (3.5)-part 1
107             X1=Alpha_pos(j)-A1*D_alpha; % Equation (3.6)-part 1
108                        
109             r1=rand(); 110             r2=rand(); 111             
112             A2=2*a*r1-a; % 計算系數A,Equation (3.3) 113             C2=2*r2; % 計算系數C,Equation (3.4) 114             
115             % Beta狼位置更新 116             D_beta=abs(C2*Beta_pos(j)-Positions(i,j)); % Equation (3.5)-part 2
117             X2=Beta_pos(j)-A2*D_beta; % Equation (3.6)-part 2       
118             
119             r1=rand(); 120             r2=rand(); 121             
122             A3=2*a*r1-a; % 計算系數A,Equation (3.3) 123             C3=2*r2; % 計算系數C,Equation (3.4) 124             
125             % Delta狼位置更新 126             D_delta=abs(C3*Delta_pos(j)-Positions(i,j)); % Equation (3.5)-part 3
127             X3=Delta_pos(j)-A3*D_delta; % Equation (3.5)-part 3             
128             
129             % 位置更新 130             Positions(i,j)=(X1+X2+X3)/3;% Equation (3.7) 131             
132  end 133  end 134     l=l+1; 135     Convergence_curve(l)=Alpha_score; 136 end 137 bestc=Alpha_pos(1,1); 138 bestg=Alpha_pos(1,2); 139 bestGWOaccuarcy=Alpha_score; 140 %% 打印參數選擇結果 141 disp('打印選擇結果'); 142 str=sprintf('Best Cross Validation Accuracy = %g%%,Best c = %g,Best g = %g',bestGWOaccuarcy*100,bestc,bestg); 143 disp(str) 144 %% 利用最佳的參數進行SVM網絡訓練 145 cmd_gwosvm = ['-c ',num2str(bestc),' -g ',num2str(bestg)]; 146 model_gwosvm = svmtrain(train_wine_labels,train_wine,cmd_gwosvm); 147 %% SVM網絡預測 148 [predict_label,accuracy] = svmpredict(test_wine_labels,test_wine,model_gwosvm); 149 % 打印測試集分類准確率 150 total = length(test_wine_labels); 151 right = sum(predict_label == test_wine_labels); 152 disp('打印測試集分類准確率'); 153 str = sprintf( 'Accuracy = %g%% (%d/%d)',accuracy(1),right,total); 154 disp(str); 155 %% 結果分析 156 % 測試集的實際分類和預測分類圖 157 figure; 158 hold on; 159 plot(test_wine_labels,'o'); 160 plot(predict_label,'r*'); 161 xlabel('測試集樣本','FontSize',12); 162 ylabel('類別標簽','FontSize',12); 163 legend('實際測試集分類','預測測試集分類'); 164 title('測試集的實際分類和預測分類圖','FontSize',12); 165 grid on 166 snapnow 167 %% 顯示程序運行時間 168 toc

 


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