samer@0: function a=bufferdata(source,L,varargin)
samer@0: % bufferdata - collect elements of sequence into sequence of arrays
samer@0: %
samer@0: % bufferdata :: 
samer@0: % 	  data [[N]]	  ~'source signal',
samer@0: %	  L:natural	     ~'buffer width',
samer@0: %	-> data [[N,L]]. ~'buffered sequence (no-overlapping)'.
samer@0: 
samer@0: 
samer@0: if nargin==1 && isa(source,'bufferdata'), a=source; 
samer@0: elseif nargin==0, a=bufferdata([],1);
samer@0: else
samer@0: 	sz=size1(source);
samer@0: 	
samer@0: 	a.dim = length(sz)+1; 
samer@0: 	a.width = L;
samer@0: 	[a.buf,source] = readcat(a.dim,source,L); 
samer@0: 
samer@0: 	if isempty(a.buf), a=[];
samer@0: 	else
samer@0: 		% sort out function table
samer@0: 		ft.datafn=@datafn;
samer@0: 		ft.stringfn=@stringfn;
samer@0: 		ft.nextfn = @nextfn;
samer@0: 
samer@0: 		a=class(a,'bufferdata',ddata(source,[sz L],ft));
samer@0: 	end
samer@0: end
samer@0: 
samer@0: function s=stringfn(a), s=sprintf('buffer(%d)',a.width);
samer@0: function x=datafn(a), x=a.buf;
samer@0: function a=nextfn(a)
samer@0: 	% read next lot of values and make an array
samer@0: 	src=source(a);
samer@0: 	[a.buf,src]=readcat(a.dim,source(a),a.width);
samer@0: 	if isempty(a.buf), a=[];
samer@0: 	else
samer@0: 		a=setsource(a,src);
samer@0: 		%!! what if i<L?
samer@0: 		%a.length=size(source(a),a.dim);
samer@0: 	end
samer@0: 
samer@0: function [buf,src]=readcat(dim,src,L)
samer@0: 	buf=[];
samer@0: 	for i=1:L
samer@0: 		if isempty(src), break; end
samer@0: 		buf=cat(dim,buf,head(src));
samer@0: 		src=next(src);
samer@0: 	end
samer@0: