Calculate tree lengths for trees in the graph specified by (AM,r)

TreeLengths.m

function tree_lengths=TreeLengths(AM,r)
%Returns total length measured for each of the L trees defined by the labeled adjacency matrix.
%Inputs:
% AM : (NxN) matrix labeled adjacency matrix (assumed symmetric)
% r : (Nx3) position vector for the N nodes
%Outputs:
% tree_lengths : (1xL)

AMlbl_direct=triu(AM,1);
tree_labels=unique(AMlbl_direct(AMlbl_direct>0));
tree_lengths=zeros(1,max(tree_labels));

for l=1:length(tree_labels)
    [ii, jj]=find(AMlbl==tree_labels(l));
    tree_lengths(tree_labels(l))=sum(sum((r(ii,:)-r(jj,:)).^2,2).^0.5)/2;
end
end