getdistance.m

用matlab实现聚类算法

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 函数名称 GetDistance(pattern1,pattern2,type)
% 参数 pattern1:样品（或聚类中心）1结构
%              pattern2:样品（或聚类中心）2结构
% type:距离模式 1:欧氏距离；2：夹角余弦距离； 3：特征值是二值时的夹角余弦距离
% 返回值       result:距离

function [result]=GetDistance(pattern1,pattern2,type)
result=0;
[m,n]=size(pattern1);
switch(type)
    case 1
        result=sum((pattern1.feature-pattern2.feature).^2);
        result=sqrt(result);
    case 2
        a=0;
        b1=0;
        b2=0;
        for i=1:m
            for j=1:n
                a=a+pattern1.feature(i,j)*pattern2.feature(i,j);
                b1=b1+pattern1.feature(i,j)*pattern1.feature(i,j);
                b2=b2+pattern2.feature(i,j)*pattern2.feature(i,j);
            end
        end
        if(b1*b2~=0)
            result=a/sqrt(b1*b2);
        else
            result=-1;
        end
    case 3
        t1=zeros(m,n);
        t2=zeros(m,n);
        a=0;
        b1=0;
        b2=0;
        for i=1:m
            for j=1:n
                if(pattern1.feature(i,j)>0.2)
                    t1(i,j)=1;
                end
                if(pattern2.feature(i,j)>0.2)
                    t2(i,j)=1;
                end
                a=a+t1(i,j)*t2(i,j);
                b1=b1+t1(i,j)*t1(i,j);
                b2=b2+t1(i,j)*t2(i,j);
            end
        end
        if(b1*b2~=0)
            result=a/sqrt(b1*b2);
        else
            result=-1;
        end
    case 4
        t1=zeros(m,n);
        t2=zeros(m,n);
        a=0;
        b1=0;
        b2=0;
        for i=1:m
            for j=1:n
                if(pattern1.feature(i,j)>0.2)
                    t1(i,j)=1;
                end
                if(pattern2.feature(i,j)>0.2)
                    t2(i,j)=1;
                end
                a=a+t1(i,j)*t2(i,j);
                b1=b1+t1(i,j)*t1(i,j);
                b2=b2+t1(i,j)*t2(i,j);
            end
        end
        if(b1+b2-a~=0)
        result=a/(b1+b2-a);
        else
            result=-1;
        end
end