image - Graph mining matlab -

i have written matlab code image analysis searches clusters in image , builds adjacency matrix clusters, discribing clusters touiching eachother in image.

i can use adjacency matrix derive graph.

for completion of algorithm have mine graph nodes of maximum degree of 2 node index either higher of neigbor (when degree 1) or between indexes of 2 neighbors.

basically in image here:

i need in matlab , important know try available adjacency matrix looking like:

1 2 3 4

1 0 0 1 1

2 0 0 0 1

3 1 0 0 1

4 1 1 1 0

probably quite simple don't see solution...

here's attempt @ this:

%# adjacency matrix m = [0 0 1 1; 0 0 0 1; 1 0 0 1; 1 1 1 0];  %# degree == 1 n = find(sum(m,2) == 1);            %# nodes degree(n)==1 nodes1 = n(n>find(m(n,:)));         %# nodes index higher of neigbor  %# degree == 2 n = find(sum(m,2) == 2);            %# nodes degree(n)==2 nb = zeros(numel(n),2); i=1:numel(n)     nb(i,:) = find( m(n(i),:) );    %# two-neighbors of node n(i) end %#nb = sort(nb,2); nodes2 = n(nb(:,1)<n & n<nb(:,2));  %# nodes index between indices of 2 neighbors  %# combine both results nodes = unique([nodes1(:);nodes2(:)]);