i have CXX and CYY values in a matrix using this values i want draw a graph and i want to add edges using minimum spanning tree approach

 i have CXX 20x20 matrix and CYY 20x20 matrix am using the plot function plot(CXX,CYY,'c*');
 after plotting this am getting image like this

after this i want to consider all the plotted points as a node and i want to add edges to this nodes using minimum spanning tree approach please give me some code.

clc;
clear all;
close all;
X=imread('a.jpg');
imfinfo('a.jpg')
figure,imshow(X)

b = imresize(X,[100,100]);
si = size(b,1);
sj = size(b,2);
figure;imshow(b);

% Binarization
th = graythresh(b);
I = im2bw(b,th);

w = 5;
h = 5;
c=si/w;
r=sj/h;
kl=bwmorph(~I,'thin',inf);
figure,imshow(kl)

R(:,:)=kl(:,:);
I=1;
U1=w;
J=1;
U2=h;
E=1;
for i=1:r
  for j=1:c
B(I:U1,J:U2)=R(I:U1,J:U2);
[x,y]=find(B==1);
CX=mean(x);
CY=mean(y);
CXX(E)=CX;
CYY(E)=CY;
T(I:U1,J:U2)=B(I:U1,J:U2);
J=J+w;
U2=U2+h;
E=E+1;
clear B x y    
    end

I=I+w;
U1=U1+h;
J=1;
U2=h;

end
imshow(R)
hold on

hold on
plot(CYY,CXX,'.c')

 input image