single,complete,average link clustring using Matlab

x=input('x=');
y=input('Y=');
subplot(4,1,1);
plot(x,y,'r*');
xlabel('x-Values')
ylabel('Y-Values')
n=length(x);
j=1;
i=1;
k=1;
  while j<n
    for i=i:n-1
       e_dis=sqrt(((x(i+1)-x(j)).^2)+((y(i+1)-y(j)).^2));
       d(k)=e_dis; %#ok<AGROW>
      k= k+1;
    end
    j=j+1;
    i=j;
  end
  display(d);
   m=min(d);
   display('Minimum Distance is');
   display(m)
   subplot(4,1,2)
       Y = pdist(x,'cityblock');
       Z = linkage(d,'complete');
       [H, T] = dendrogram(Z);
       xlabel(' complete_link Dendrogram');
 subplot(4,1,3)
 Y = pdist(x,'cityblock');
       Z = linkage(d,'Average');
       [H, T] = dendrogram(Z);
       xlabel('Average Link_Dendrogram');
       subplot(4,1,4)
       Y = pdist(x,'cityblock');
       Z = linkage(d,'single');
       [H, T] = dendrogram(Z);
       xlabel(' Single Link_Dendrogram');