MATLAB最大最小距离法进行聚类分析-模式识别导论（齐敏）课后题2.1

题目

代码

%%
X=[0,0;1,1;2,2;3,7;3,6;4,6;5,7;6,3;7,3;7,4];
sita=1/2;

%第一第二聚类中心
Z=X(randi(length(X(:,1))),:);
len=length(X);
distance=zeros(len,1);
for i=1:len
    distance(i)=sqrt((X(i,1)-Z(1,1))^2+(X(i,2)-Z(1,2))^2);
end
k=find(distance==max(distance));
Z=[Z;X(k,:)];
D=sqrt((Z(1,1)-Z(2,1))^2+(Z(1,2)-Z(2,2))^2);
%%
%其余聚类中心
maxmin_D=D;
while maxmin_D>sita*D
    k=size(Z,1);
    distance=zeros(len,k);
    for i=1:len
        for j=1:k
            distance(i,j)=sqrt((X(i,1)-Z(j,1))^2+(X(i,2)-Z(j,2))^2);
        end
    end
    distance_1=min(distance,[],2);
    maxmin_D=max(distance_1);
    if maxmin_D>sita*D
        w=find(distance_1==maxmin_D);
        Z=[Z;X(w,:)];
    end
end

%%
%分类
k=size(Z,1);
Y=zeros(len,3);
for i=1:len
    distance=zeros(1,k);
    for j=1:k
        distance(j)=sqrt((X(i,1)-Z(j,1))^2+(X(i,2)-Z(j,2))^2);
    end
    Y(i,1:2)=X(i,:);
    Y(i,3)=find(distance==min(distance)); 
end

%%
%更新分类中心
Z1=zeros(k,2);
K=zeros(k,1);
for i=1:len
    K(Y(i,3))=K(Y(i,3))+1;
    Z1(Y(i,3),1)=Z1(Y(i,3),1)+Y(i,1);
    Z1(Y(i,3),2)=Z1(Y(i,3),2)+Y(i,2);
end
for i=1:k
    Z1(i,1)=Z1(i,1)/K(i);
    Z1(i,2)=Z1(i,2)/K(i);
end

%%
%再次分类
Y1=zeros(len,3);
for i=1:len
    distance=zeros(1,k);
    for j=1:k
        distance(j)=sqrt((X(i,1)-Z1(j,1))^2+(X(i,2)-Z1(j,2))^2);
    end
    Y1(i,1:2)=X(i,:);
    Y1(i,3)=find(distance==min(distance)); 
end 

结果

《模式识别导论》齐敏