tomwalters@0: % method of class @signal
tomwalters@0: % usage: sigresult=tilt(sig,tilttime)
tomwalters@0: % puts the signal upright!
tomwalters@0: % in the auditory image model, all activities become
tomwalters@0: % smaller with the distance
tomwalters@0: % usually with a decrease of 100% in 40 ms
tomwalters@0: % if you call tilt with tilt(sig,0.04), this tilt is reversed
tomwalters@0: %
tomwalters@0: %   INPUT VALUES:
tomwalters@0: %       sig:  original @signal
tomwalters@0: %       tilttime: time in seconds that the old signal is assumed to go from 100% to 0
tomwalters@0: %       [default: 0.04]
tomwalters@0: %
tomwalters@0: %   RETURN VALUE:
tomwalters@0: %       sigresult:  @signal
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=antitilt(sig,tilttime)
tomwalters@0: 
tomwalters@0: if nargin<2
tomwalters@0:     tilttime=0.04;
tomwalters@0: end
tomwalters@0: 
tomwalters@0: vals=sig.werte;
tomwalters@0: 
tomwalters@0: if getminimumtime(sig)>0
tomwalters@0:     return
tomwalters@0: end
tomwalters@0: durationtotilt=abs(getminimumtime(sig));
tomwalters@0: tiltnr=time2bin(sig,0); % so viele Punkte werden getiltet
tomwalters@0: dt=tilttime-durationtotilt; % übrige Zeit, die links aus dem Bild rausgeht
tomwalters@0: dnull=dt/tilttime;
tomwalters@0: ti=linspace(dnull,1,tiltnr)';
tomwalters@0: vals(1:tiltnr)=vals(1:tiltnr)./ti;
tomwalters@0: % figure
tomwalters@0: % subplot(2,1,1)
tomwalters@0: % plot(sig);
tomwalters@0: sig.werte=vals;
tomwalters@0: % subplot(2,1,2)
tomwalters@0: % plot(sig);
tomwalters@0: 
tomwalters@0: 
tomwalters@0: