matthiasm@8: function plot_matrix(G, bw)
matthiasm@8: % PLOT_MATRIX Plot a 2D matrix as a grayscale image, and label the axes
matthiasm@8: %
matthiasm@8: % plot_matrix(M)
matthiasm@8: %
matthiasm@8: % For 0/1 matrices (eg. adjacency matrices), use
matthiasm@8: % plot_matrix(M,1)
matthiasm@8: 
matthiasm@8: if nargin < 2, bw = 0; end
matthiasm@8: 
matthiasm@8: if 0
matthiasm@8:   imagesc(G)
matthiasm@8:   %image(G)
matthiasm@8:   %colormap([1 1 1; 0 0 0]); % black squares on white background
matthiasm@8:   %colormap(gray)
matthiasm@8:   grid on
matthiasm@8:   n = length(G);
matthiasm@8:   
matthiasm@8:   % shift the grid lines so they don't intersect the squares
matthiasm@8:   set(gca,'xtick',1.5:1:n);
matthiasm@8:   set(gca,'ytick',1.5:1:n);
matthiasm@8:   
matthiasm@8:   % Turn off the confusing labels, which are fractional
matthiasm@8:   % Ideally we could shift the labels to lie between the axis lines...
matthiasm@8: %  set(gca,'xticklabel', []);
matthiasm@8: %  set(gca,'yticklabel', []);
matthiasm@8: else
matthiasm@8:   % solution provided by Jordan Rosenthal <jr@ece.gatech.edu>
matthiasm@8:   % You can plot the grid lines manually:
matthiasm@8:   % This uses the trick that a point with a value nan does not get plotted.
matthiasm@8:   imagesc(G);
matthiasm@8:   if bw
matthiasm@8:     colormap([1 1 1; 0 0 0]);
matthiasm@8:   end
matthiasm@8:   n = length(G);
matthiasm@8:   x = 1.5:1:n;
matthiasm@8:   x = [ x; x; repmat(nan,1,n-1) ];
matthiasm@8:   y = [ 0.5 n+0.5 nan ].';
matthiasm@8:   y = repmat(y,1,n-1);
matthiasm@8:   x = x(:);
matthiasm@8:   y = y(:);
matthiasm@8:   line(x,y,'linestyle',':','color','k');
matthiasm@8:   line(y,x,'linestyle',':','color','k');
matthiasm@8:   set(gca,'xtick',1:n)
matthiasm@8:   set(gca,'ytick',1:n)
matthiasm@8: end
matthiasm@8: 
matthiasm@8: