tomwalters@0: % method of class @signal
tomwalters@0: % function sig=genbandpassnoise(sig,varargin)
tomwalters@0: %   INPUT VALUES:
tomwalters@0: %       sig: @signal with length and samplerate 
tomwalters@0: %   RETURN VALUE:
tomwalters@0: %       sig:  @signal 
tomwalters@0: %
tomwalters@0: % (c) 2003-2008, University of Cambridge, Medical Research Council 
tomwalters@0: % Maintained by Tom Walters (tcw24@cam.ac.uk), written by Stefan Bleeck (stefan@bleeck.de)
tomwalters@0: % http://www.pdn.cam.ac.uk/cnbh/aim2006
tomwalters@0: % $Date: 2008-06-10 18:00:16 +0100 (Tue, 10 Jun 2008) $
tomwalters@0: % $Revision: 585 $
tomwalters@0: 
tomwalters@0: function sig=generateAMnoise(sig,fre,modgrad)
tomwalters@0: 
tomwalters@0: len=getlength(sig);
tomwalters@0: sr=getsr(sig);
tomwalters@0: 
tomwalters@0: % generate white noise:
tomwalters@0: vals=getvalues(sig);
tomwalters@0: vals=rand(size(vals)).*2-1;
tomwalters@0: sig=setvalues(sig,vals);
tomwalters@0: 
tomwalters@0: envelope=generatesinus(sig,fre,1,0);
tomwalters@0: envelope=(envelope+1)/2;
tomwalters@0: 
tomwalters@0: sig=sig*envelope;
tomwalters@0: 
tomwalters@0: 
tomwalters@0: sig=setname(sig,sprintf('AM noise Frequency %4.1f Hz',fre));
tomwalters@0: 
tomwalters@0: return