function plot_adjacency(Adj)

held = ishold;

%plot genesis links
[i,j] = find(Adj == 4);
plot(i,j, '.');

hold on;

%plot verified links
[i,j] = find(Adj == 3 | Adj == 2);
plot(i,j, 'o');

%plot unverified links
[i,j] = find(Adj == 1);
plot(i,j, 'x');

if ~held, hold off; end

legend('genesis','verified','unverified')

axis ij, axis tight, axis square