wolffd@0: function [xvals, yvals, color] = hintmat(w);
wolffd@0: %HINTMAT Evaluates the coordinates of the patches for a Hinton diagram.
wolffd@0: %
wolffd@0: %	Description
wolffd@0: %	[xvals, yvals, color] = hintmat(w)
wolffd@0: %	  takes a matrix W and returns coordinates XVALS, YVALS for the
wolffd@0: %	patches comrising the Hinton diagram, together with a vector COLOR
wolffd@0: %	labelling the color (black or white) of the corresponding elements
wolffd@0: %	according to their sign.
wolffd@0: %
wolffd@0: %	See also
wolffd@0: %	HINTON
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: w = flipud(w);
wolffd@0: [nrows, ncols] = size(w);
wolffd@0: 
wolffd@0: scale = 0.45*sqrt(abs(w)/max(max(abs(w))));
wolffd@0: scale = scale(:);
wolffd@0: color = 0.5*(sign(w(:)) + 3);
wolffd@0: 
wolffd@0: delx = 1;
wolffd@0: dely = 1;
wolffd@0: [X, Y] = meshgrid(0.5*delx:delx:(ncols-0.5*delx), 0.5*dely:dely:(nrows-0.5*dely));
wolffd@0: 
wolffd@0: % Now convert from matrix format to column vector format, and then duplicate
wolffd@0: % columns with appropriate offsets determined by normalized weight magnitudes. 
wolffd@0: 
wolffd@0: xtemp = X(:);
wolffd@0: ytemp = Y(:);
wolffd@0: 
wolffd@0: xvals = [xtemp-delx*scale, xtemp+delx*scale, ...
wolffd@0:          xtemp+delx*scale, xtemp-delx*scale];
wolffd@0: yvals = [ytemp-dely*scale, ytemp-dely*scale, ...
wolffd@0:          ytemp+dely*scale, ytemp+dely*scale];
wolffd@0: