Daniel@0: function [edge_id, nedges] = assignEdgeNums(adj_mat)
Daniel@0: % give each edge a unique number
Daniel@0: % we number (i,j) for j>i first, in row, column order.
Daniel@0: % Then we number the reverse links
Daniel@0: 
Daniel@0: nnodes = length(adj_mat);
Daniel@0: edge_id = zeros(nnodes);
Daniel@0: e = 1;
Daniel@0: for i=1:nnodes
Daniel@0:   for j=i+1:nnodes
Daniel@0:     if adj_mat(i,j)
Daniel@0:       edge_id(i,j) = e;
Daniel@0:       e = e+1;
Daniel@0:     end
Daniel@0:   end
Daniel@0: end
Daniel@0: 
Daniel@0: nedges = e-1;
Daniel@0: tmp = edge_id;
Daniel@0: ndx = find(tmp);
Daniel@0: tmp(ndx) = tmp(ndx)+nedges;
Daniel@0: edge_id = edge_id + triu(tmp)';
Daniel@0: 
Daniel@0: 
Daniel@0: if 0
Daniel@0: ndx = find(adj_mat);
Daniel@0: nedges = length(ndx);
Daniel@0: nnodes = length(adj_mat);
Daniel@0: edge_id = zeros(1, nnodes*nnodes);
Daniel@0: edge_id(ndx) = 1:nedges; 
Daniel@0: edge_id = reshape(edge_id, nnodes, nnodes);
Daniel@0: end