PCA求初始中心

clc
clear
close all 
rgb=imread('4.jpg');
[m,n,p]=size(rgb);
RGB=reshape(rgb,m*n,3);
RGB=double(RGB);
S=cov(RGB);
s = diag(S);
if (any(s~=1))
   corrData= S./ sqrt(s * s');
end
%  [aa,v]=jac(corrData);  %%利用雅可比矩阵求得的结果
 [v1,d]=eig(corrData);
[newD,IX] = sort(diag(v1),'ascend');
newD=diag(newD);
V=v1(:,IX);
newData=RGB*V;
[maxEntry,idxmax]=max(newData(:,1));
[minEntry,idxmin]=min(newData(:,1));
K=3;
d=(maxEntry-minEntry)/K;
c=zeros(4,1);
c(1,1)=minEntry;
for i=2:K+1
    c(i,1)=c(i-1,1)+d;
end
%%依据第一段的主维度的均值
first=(find(newData(:,1)>=c(1,1)&newData(:,1)<c(2,1)));
firstdata=newData(first,:);
meandata1=mean(firstdata);
%%依据第二段的主维度的均值
second=(find(newData(:,1)>=c(2,1)&newData(:,1)<c(3,1)));
secdata=newData(second,:);
meanfdata2=mean(secdata);
%%依据第三段的值
third=(find(newData(:,1)>=c(3,1)&newData(:,1)<c(4,1)));
thdata=newData(third,:);
meanfdata3=mean(thdata);
newM=[meandata1;meanfdata2;meanfdata3];
temp= inv(V);       %求矩阵的逆
M=newM*temp;