function pkernelproj(model,options)% PKERNELPROJ Plots isolines of kernel projection.%% Synopsis:%  pkernelproj(model)%  pkernelproj(model,options)%% Description:%  This function plots isolines corresponding to points%  having equal value of projection onto kernel basis%  (e.g. onto principal component in Kernel PCA). %  See 'help kernelproj' for more help on kernel projection.%% Input:%  model [struct] Defines kernel data projection. %% options [struct] Controls apperance:%  .contours [1x1] Number of plotted contours (Default 10).%  .xgrid [1x1] Density of sampling in x-axis (default 25).x%  .ygrid [1x1] Density of sampling in y-axis (default 25).% % Example:%  help kpca;%  % See also %  KERNELPROJ, KPCA, GDA.%% About: Statistical Pattern Recognition Toolbox% (C) 1999-2003, Written by Vojtech Franc and Vaclav Hlavac% <a href="http://www.cvut.cz">Czech Technical University Prague</a>% <a href="http://www.feld.cvut.cz">Faculty of Electrical Engineering</a>% <a href="http://cmp.felk.cvut.cz">Center for Machine Perception</a>% Modifications:% 4-may-2004, VF% 22-jan-2003, VF% 8-July-2001, V.Franc if nargin < 2, options = []; endif ~isfield(options,'contours'), options.contours=10; endif ~isfield(options,'xgrid'), options.xgrid=25; endif ~isfield(options,'ygrid'), options.ygrid=25; endoldhold=ishold; hold on;% Testing points - grid [xgrid x ygrid].w = axis;xrange=w(1):(w(2)-w(1))/options.xgrid:w(2);yrange=w(3):(w(4)-w(3))/options.ygrid:w(4);[X,Y] = meshgrid(xrange,yrange);Xtst=[reshape(X,1,prod(size(X)));reshape(Y,1,prod(size(Y)))];% Z = kernelproj(Xtst,model);% Plot contours of selected features.for i=1:size(Z,1),  map = reshape(Z(i,:), length(yrange), length(xrange));  contour(xrange, yrange, map, options.contours, marker_color(i));end% if ~oldhold, hold off; endreturn;