%FEATSELF Forward feature selection% % 	[W,R] = featself(A,crit,k,T)% % Forward selection of k features using the dataset A. crit sets the % criterion used by the feature evaluation routine feateval. If the % data set T is given, it is used as test set for feateval. For k=0 % the optimal feature set (maximum value of feateval) is returned. % The result W can be used for selecting features by B*W.  Defaults: % crit='NN', k=0. In R the search is step by step reported:% % 	R(:,1) : number of features% 	R(:,2) : criterion value% 	R(:,3) : added / deleted feature% % See also mappings, datasets, feateval, featselm, featselb, % featselo, featselp, featseli% Copyright: R.P.W. Duin, duin@ph.tn.tudelft.nl% Faculty of Applied Physics, Delft University of Technology% P.O. Box 5046, 2600 GA Delft, The Netherlandsfunction [W,R] = featself(A,crit,ksel,T)if nargin < 2, crit = 'NN'; endif nargin < 3, ksel = 0; endif nargin < 4, T = []; endif nargin == 0 | isempty(A)	W = mapping('featself',{crit,ksel,T});    returnend[nlaba,lablist,m,k,c,prob,featlist] = dataset(A);if ~isempty(T)	[mt,kt] = size(T);	if kt ~= k		error('Data sizes do not match')	endendCmax = 0;I = [1:k];J = [];R = [];Iopt = J;while length(J) < k	C = zeros(1,length(I));	for j = 1:length(I)		L = [J,I(j)];		if isempty(T)			C(j) = feateval(A(:,L),crit);		else			C(j) = feateval(A(:,L),crit,T(:,L));		end		if C(j) > Cmax			Cmax = C(j);			Iopt = L;		end	end	[mx,j] = max(C);	J = [J,I(j)];  	I(j) = [];	r = [length(J),mx,J(end)];	%disp(r)	R = [R; r];	if length(J) == ksel		W = mapping('featsel',J,featlist(J,:),k,length(J));		return	endendW = mapping('featsel',Iopt,featlist(Iopt,:),k,length(Iopt));return