I got 3 square cluster from 12 (x,y) points. How can I find out which points it is taking for making the clusters?

Hi, I have gotten 12 points from the images. Then I ran the cluster program for those points. My cluster program is below:

X = [112 161;154 166;107 214;149 218;179 277;163 284;188 300;172 307;268 314;241 323;273 340;246 349]
D= pdist(X)
P=squareform (D)
Z= linkage (D)
T = cluster(Z,'maxclust',3)
Q= sprintf('X(i,1),X(i,2)');
axis ([0 700 0 540])
figure 
for i=1:12
    if T(i)==1
        axis ([0 700 0 540])
        plot (X(i,1),X(i,2),'Marker','p','Color', ('green'),'MarkerSize',20);
        Q= sprintf('X(i,1),X(i,2)');
    hold on;
    end
     if T(i)==2
         axis ([0 700 0 540])   
         plot (X(i,1),X(i,2),'Marker','p','Color', ('red'),'MarkerSize',20);
     hold on; 
     end
     if T(i)==3
         axis ([0 700 0 540])       
         plot (X(i,1),X(i,2),'Marker','p','Color', ('blue'),'MarkerSize',20);
  hold on;
     end
end
disp(Q);

Here X is the 12 points. After doing this it is making perfect 3 squares for every T(i). I gave the instruction to show the every (X(i,1),X(i,2) as Q. By this I could find out the exact 4 points of each and every squares. But unfortunately it is not showing those 4 points of each squares it is taking from X.

Can anyone help me that how can I see the 4 points of the squares it is taking from the 12 points? And how can I named them as square 1, square 2 and square 3?

Thanks in advanced.

Answer 1

[Tom Lane]

I may not follow your request. The variable T indicates which row of X belongs to each cluster. If you want to show that on the plot, you could replace your plot command with something like

text(X(i,1),X(i,2),num2str(i),'Color','g')

This would show the number instead of the marker.

[Shamim Rahman]

Hi, Thank you very much for your answer. Can you please suggest me any books or web links where I can get idea about this type of image processing problems? Because now I have to show that which one is number 1, which one is number 2 and which one is number 3 squares of 12 images.

If you can give me any name of books. Then it will be so helpful for me.

Thank you again for your answer...

[Tom Lane]

I'm not an expert with images. I can only tell you that the numbering produced by the cluster function is arbitrary. All the points assigned to cluster 1 are in the same cluster, but there is no sense in which that cluster can be regarded as first.