samer@1: % signal - Base class for signal
samer@1: %
samer@1: % signal :: signal(C:natural,R:nonneg).
samer@1: %
samer@1: % The signal(C,R) type denotes the type of a signal with C
samer@1: % channels and a sampling rate of R. 
samer@1: %
samer@1: % The base signal class cannot be used without subclassing since
samer@1: % any attempt to instantiate the live signal generator will throw
samer@1: % an exception.
samer@1: %
samer@1: % METHODS
samer@1: %    channels :: signal(C,R) -> natural.
samer@1: %    rate     :: signal(C,R) -> nonneg. 
samer@1: %    construct:: signal(C,R) -> livesig(C).
samer@1: %    length   :: signal(C,R) -> natural.
samer@1: %    gather   :: signal(C,R), options -> [[C,N]].
samer@1: %    gathern  :: N:natural, signal(C,R), options -> [[C,N]], natural.
samer@1: %
samer@1: % livesig(C) :== struct {
samer@1: %    start   :: void->void;
samer@1: %    stop    :: void->void;
samer@1: %    dispose :: void->void;
samer@1: %    reader  :: N:natural -> (void->[[C,N]]);
samer@1: % }
samer@1: 
samer@1: classdef signal
samer@3: 	methods (Abstract)
samer@3: 		c=channels(s)
samer@3: 		u=construct(s)
samer@3: 		r=rate(s)
samer@1: 	end
samer@3: 
samer@1: 	methods
samer@1: 		function s=signal, end
samer@1: 
samer@1: 		function s=and(s1,s2), s=sigcat(s1,s2); end
samer@1: 		function y=cache(x), y=reclock(rate(x),sigarray(gather(x))); end
samer@1: 		function display(a)
samer@1: 			disp(sprintf('    %s :: signal(%s,%s)',tostring(a),fmt(channels(a)),fmt(rate(a))));
samer@1: 			function s=fmt(x), if isnan(x), s='_'; else s=num2str(x); end; end
samer@1: 		end
samer@1: 
samer@1: 		function y=map(f,x), y=sigmap(f,x); end
samer@1: 		function s=mpower(a,b), s=resample(b,a); end
samer@1: 		function s=or(s1,s2), s=sigbinop(@vertcat,s1,s2,@plus); end
samer@1: 		function s2=reclock(r,s1), s2=sigreclock(r,s1); end
samer@1: 		function y=drop(n,x), y=sigdrop(n,x); end
samer@1: 		function y=take(n,x), y=sigtake(n,x); end
samer@1: 
samer@1: 		function y=dropt(t,x), 
samer@1: 			if isnan(rate(x)), error('Cannot dropt without definite sampling rate'); end
samer@1: 			y=sigdrop(round(t*rate(x)),x);
samer@1: 		end
samer@1: 			
samer@1: 		function y=taket(t,x), 
samer@1: 			if isnan(rate(x)), error('Cannot taket without definite sampling rate'); end
samer@1: 			y=sigtake(round(t*rate(x)),x);
samer@1: 		end
samer@1: 			
samer@1: 		function y=cycle(x), 
samer@1: 			y=siglzcat(x,@cyclef);
samer@1: 			function [s1,sx]=cyclef, s1=x; sx=@cyclef; end
samer@1: 		end
samer@1: 
samer@1: 		function s2=resample(f2,s1,varargin)
samer@1: 			if isnan(rate(s1)), error('no sample rate set'); end
samer@1: 			if rate(s1)==f2, s2=s1;
samer@1: 			else, s2=sigresample(f2,s1,varargin{:}); end
samer@1: 		end
samer@43: 
samer@43: 		function varargout=specgrm(x,varargin)
samer@43: 			 [varargout{1:nargout}]=specgrm(gather(x),varargin{:},'fs',rate(x));
samer@43: 		 end
samer@1: 	end
samer@1: end