tomwalters@0: % method of class @signal
tomwalters@0: % function sig=generatesweep(sig,fre1,fre2,amplitude,phase)
tomwalters@0: %   INPUT VALUES:
tomwalters@0: %       sig: original @signal with length and samplerate 
tomwalters@0: %       fre1: start frequency (Hz)
tomwalters@0: %       fre2: stop frequency (Hz)
tomwalters@0: %       amplitude: [1]
tomwalters@0: %       phase: startphase [0]
tomwalters@0: %       phases must be in degrees!
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
tomwalters@0: 
tomwalters@0: 
tomwalters@0: function sig=generatesweep(sig,fre1,fre2,amplitude,phase)
tomwalters@0: 
tomwalters@0: if nargin < 5
tomwalters@0:     phase=0;
tomwalters@0: end
tomwalters@0: if nargin < 4
tomwalters@0:     amplitude=1;
tomwalters@0: end
tomwalters@0: 
tomwalters@0: if nargin <3 
tomwalters@0:     disp('GenerateSweep: Error: usage: sig=generatesweep(sig,fre1,fre2[,amplitude,phase])')
tomwalters@0: end
tomwalters@0: 
tomwalters@0: nr_points=getnrpoints(sig);
tomwalters@0: sr=getsr(sig);
tomwalters@0: length=getlength(sig);
tomwalters@0: 
tomwalters@0: from=0+phase;
tomwalters@0: 
tomwalters@0: fre_space=linspace(fre1,fre2,nr_points);    % the change of frequency
tomwalters@0: t_space=linspace(0,length,nr_points);    % a linear function of time
tomwalters@0: val=2*pi*t_space.*fre_space;
tomwalters@0: 
tomwalters@0: val=val + phase;
tomwalters@0: 
tomwalters@0: data=sin(val);
tomwalters@0: 
tomwalters@0: data=data*amplitude;
tomwalters@0: 
tomwalters@0: sig=signal(data);
tomwalters@0: sig=setsr(sig,sr);
tomwalters@0: sig=setname(sig,sprintf('Sweep from %4.2f kHz to %4.2f kHz',fre1/1000,fre2/1000));