tomwalters@0: % method of class @signal
tomwalters@0: % 
tomwalters@0: %   INPUT VALUES:
tomwalters@0: %  
tomwalters@0: %   RETURN VALUE:
tomwalters@0: %
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 t=getzerocrossings(signal,var)
tomwalters@0: % gets the zero crossings of the signal.
tomwalters@0: % in Case, the Signal has many zeros and only few 
tomwalters@0: % bumps, like in a klicktrain, only the last zero is counted
tomwalters@0: % if var is there, then not real zero, but a value of var is taken
tomwalters@0: 
tomwalters@0: if nargin < 2 
tomwalters@0:     var=0;
tomwalters@0: end
tomwalters@0: 
tomwalters@0: werte=getdata(signal);
tomwalters@0: 
tomwalters@0: nr= getnrpoints(signal); % so many points
tomwalters@0: a=0;
tomwalters@0: count=1;
tomwalters@0: sr=getSR(signal);
tomwalters@0: for i=1:nr
tomwalters@0:     b=werte(i);
tomwalters@0:     if a <= var & b > var
tomwalters@0:         t(count)=bin2time(signal,i);
tomwalters@0:         count=count+1;
tomwalters@0:     end
tomwalters@0:     % shift the last values
tomwalters@0:     a=b;
tomwalters@0: end