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