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: %
bleeck@3: % This external file is included as part of the 'aim-mat' distribution package
bleeck@3: % (c) 2011, University of Southampton
bleeck@3: % Maintained by Stefan Bleeck (bleeck@gmail.com)
bleeck@3: % download of current version is on the soundsoftware site: 
bleeck@3: % http://code.soundsoftware.ac.uk/projects/aimmat
bleeck@3: % documentation and everything is on http://www.acousticscale.org
bleeck@3: 
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