wolffd@0: function [h1, h2] = mlphint(net);
wolffd@0: %MLPHINT Plot Hinton diagram for 2-layer feed-forward network.
wolffd@0: %
wolffd@0: %	Description
wolffd@0: %
wolffd@0: %	MLPHINT(NET) takes a network structure NET and plots the Hinton
wolffd@0: %	diagram comprised of two figure windows, one displaying the first-
wolffd@0: %	layer weights and biases, and one displaying the second-layer weights
wolffd@0: %	and biases.
wolffd@0: %
wolffd@0: %	[H1, H2] = MLPHINT(NET) also returns handles H1 and  H2 to the
wolffd@0: %	figures which can be used, for instance, to delete the  figures when
wolffd@0: %	they are no longer needed.
wolffd@0: %
wolffd@0: %	To print the figure correctly, you should call SET(H,
wolffd@0: %	'INVERTHARDCOPY', 'ON') before printing.
wolffd@0: %
wolffd@0: %	See also
wolffd@0: %	DEMHINT, HINTMAT, MLP, MLPPAK, MLPUNPAK
wolffd@0: %
wolffd@0: 
wolffd@0: %	Copyright (c) Ian T Nabney (1996-2001)
wolffd@0: 
wolffd@0: % Set scale to be up to 0.9 of maximum absolute weight value, where scale
wolffd@0: % defined so that area of box proportional to weight value.
wolffd@0: 
wolffd@0: % Use no more than 640x480 pixels
wolffd@0: xmax = 640; ymax = 480;
wolffd@0: 
wolffd@0: % Offset bottom left hand corner
wolffd@0: x01 = 40; y01 = 40;
wolffd@0: x02 = 80; y02 = 80;
wolffd@0: 
wolffd@0: % Need to allow 5 pixels border for window frame: but 30 at top
wolffd@0: border = 5;
wolffd@0: top_border = 30;
wolffd@0: 
wolffd@0: ymax = ymax - top_border;
wolffd@0: xmax = xmax - border;
wolffd@0: 
wolffd@0: % First layer
wolffd@0: 
wolffd@0: wb1 = [net.w1; net.b1];
wolffd@0: [xvals, yvals, color] = hintmat(wb1');
wolffd@0: % Try to preserve aspect ratio approximately
wolffd@0: if (8*net.nhidden < 6*(net.nin + 1))
wolffd@0:   delx = xmax; dely = xmax*net.nhidden/(net.nin + 1);
wolffd@0: else
wolffd@0:   delx = ymax*(net.nin + 1)/net.nhidden; dely = ymax;
wolffd@0: end
wolffd@0: 
wolffd@0: h1 = figure('Color', [0.5 0.5 0.5], ...
wolffd@0:   'Name', 'Hinton diagram: first-layer weights and biases', ...
wolffd@0:   'NumberTitle', 'off', ...
wolffd@0:   'Colormap', [0 0 0; 1 1 1], ...
wolffd@0:   'Units', 'pixels', ...
wolffd@0:   'Position', [x01 y01 delx dely]);
wolffd@0: set(gca, 'Visible', 'off', 'Position', [0 0 1 1]);
wolffd@0: hold on
wolffd@0: 
wolffd@0: cmap = [0 0 0; 1 1 1];
wolffd@0: colors(1, :, :) = cmap(color, :);
wolffd@0: patch(xvals', yvals', colors, 'Edgecolor', 'none');
wolffd@0: axis equal;
wolffd@0: xpos = net.nin;
wolffd@0: line([xpos xpos], [0 net.nhidden], 'color', 'red', 'linewidth', 3);
wolffd@0: 
wolffd@0: % Second layer
wolffd@0: 
wolffd@0: wb2 = [net.w2; net.b2];
wolffd@0: [xvals, yvals, color] = hintmat(wb2');
wolffd@0: if (8*net.nout < 6*(net.nhidden + 1))
wolffd@0:   delx = xmax; dely = xmax*net.nout/(net.nhidden + 1);
wolffd@0: else
wolffd@0:   delx = ymax*(net.nhidden + 1)/net.nout; dely = ymax;
wolffd@0: end
wolffd@0: 
wolffd@0: h2 = figure('Color', [0.5 0.5 0.5], ...
wolffd@0:   'Name', 'Hinton diagram: second-layer weights and biases', ...
wolffd@0:   'NumberTitle', 'off', ...
wolffd@0:   'Colormap', [0 0 0; 1 1 1], ...  
wolffd@0:   'Units', 'pixels', ...
wolffd@0:   'Position', [x02 y02 delx dely]);
wolffd@0: set(gca, 'Visible', 'off', 'Position', [0 0 1 1]);
wolffd@0: 
wolffd@0: hold on
wolffd@0: colors2(1, :, :) = cmap(color, :);
wolffd@0: patch(xvals', yvals', colors2, 'Edgecolor', 'none');
wolffd@0: axis equal;
wolffd@0: xpos = net.nhidden;
wolffd@0: line([xpos xpos], [0 net.nout], 'color', 'red', 'linewidth', 3);
wolffd@0: