%SEQUENTIAL Sequential mapping%%   V = SEQUENTIAL(W1,W2) %   B = SEQUENTIAL(A,W)%% INPUT%   W,W1,W2  Mappings%   A        Dataset%% OUTPUT%   V        Sequentially combined mapping%   B        Dataset%% DESCRIPTION% The two mappings W1 and W2 are combined into a single mapping V. Note % that SEQUENTIAL(W1,W2) is equivalent to W1*W2. If W2 is a mapping of % a type 'combiner', it is called to make a combination attempt.%	SEQUENTIAL(A,W) maps the dataset A by the sequential mapping W.%% This routine is automatically called to execute W = W1*W2 or B = A*W2 in% case W2 is a sequential mapping. It should not be directly called by users.%% SEE ALSO% MAPPINGS, DATASETS% Copyright: R.P.W. Duin, duin@ph.tn.tudelft.nl% Faculty of Applied Sciences, Delft University of Technology% P.O. Box 5046, 2600 GA Delft, The Netherlands% $Id: sequential.m,v 1.4 2007/04/01 20:31:11 duin Exp $function w = sequential(w1,w2,w3)		prtrace(mfilename);		% Just necessary to inform MAP.	if (nargin == 0) 		w = mapping(mfilename,'combiner');		return;	end	[m1,k1] = size(w1); 	[m2,k2] = size(w2);	if (~isa(w2,'mapping'))		error('Second argument should be a mapping.')	end	if isa(w1,'mapping') 		% Definition    if isempty(w1) % treat empty mapping as unity mapping      w = w2;    elseif (iscombiner(w2))			% Execute the mapping W2.			map = getmapping_file(w2);			pars = getdata(w2);			w = feval(map,w1,pars{:});		else 			% W2 is just a general mapping.			if (k1 > 0) & (m2 > 0) & (k1 ~= m2)				error('Inner mapping/data sizes do not agree.')			end			% Define the mapping type after combining W1 and W2.			if (isuntrained(w1)) | (isuntrained(w2))				mappingtype = 'untrained';			elseif (istrained(w1)) | (istrained(w2))				mappingtype = 'trained';			else				mappingtype = 'fixed';			end						if (m2 == 0 | k2 == 0) & (m1 ~= 0) & (k1 ~= 0) 				% TRAINED * FIXED				labels   = getlabels(w1);				size_in  = getsize_in(w1);				size_out = getsize_out(w1);			elseif (m2 ~= 0) & (k2 ~= 0) & (m1 == 0 | k1 == 0) 				% FIXED * TRAINED				labels   = getlabels(w2);				size_in  = getsize_in(w2);				size_out = getsize_out(w2);			elseif isfixed(w2)         				% TRAINED * FIXED				labels   = getlabels(w1);				size_in  = getsize_in(w1);				size_out = getsize_out(w2);			else                    					% TRAINED * TRAINED				labels = getlabels(w2);				size_in = getsize_in(w1);				size_out = getsize_out(w2);			end			w = mapping(mfilename,mappingtype,{w1,w2},labels,size_in,size_out);		end  elseif isempty(w2) % treat empty mapping as unity mapping    w = w1;  else		% Execution. We are here, when SEQUENTIAL(A,V) is called.		if nargin == 3 % needed as MAP breaks down sequential mappings			w2 = w2*w3;  % restore them!		end		a = w1;		if (~isa(a,'double')) & (~isa(a,'dataset'))			error('Just datasets or doubles can be mapped.')		end		% V can be a more complex mapping.		v = +w2; v1 = v{1}; v2 = v{2};		if (isuntrained(v1))			if (isuntrained(v2))				u = a*v1;				w = u*(a*u*v2);			else				w = a*v1*v2;			end		else			if (isuntrained(v2))				w = v1*(a*v1*v2);			else				w = a*v1*v2;				featlabels = getlabels(w2);				if (isdataset(w)) & ~isempty(featlabels)					w = setfeatlab(w,featlabels);				end			end		end	endreturn;