gld_xl.m

用matlab实现了五类灰色关联度模型的计算

% 斜率关联度
% P20 -- The Study on the Grey Relational Degree and Its Application 

function r1 = gld_xl(x)
s = size(x);
len = s(2);
num = s(1);
% 无量纲化
for i = 1: num
    x(i,:) = x(i,:)./x(i,1);
end
% 求一阶差分
dx(num,len-1) = 0;
for i = 1 : num
    for j = 1 : len - 1
        dx(i,j) = x(i,j+1) - x(i,j);
    end
end
% 计算关联系数
r(1,1:len-1) = 1;
for i = 2 : num
    for k = 1 : len - 1
        r(i,k) = 1/(1 + abs(dx(1,k)/x(1,k+1) - dx(i,k)/x(i,k+1)));
    end
end
% 计算关联度
r1 = sum(r(2:num,:),2)/(len - 1);