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 [val,hoch,breit,widthvals]=qvalue(sig,where,howmuch)
tomwalters@0: % usage: val=qvalue(sig,where,howmuch)
tomwalters@0: % calculates the q-value, that is the hight divided by the width
tomwalters@0: % of the signal at a point given by where (in seconds!)
tomwalters@0: % howmuch is the indicator, how much the signal must be dropped 0.5 or such
tomwalters@0: % returns the width in seconds, or 0, when the signal does not reach the value
tomwalters@0: % widthvals has two x-values: where the width hits the signal
tomwalters@0: 
tomwalters@0: vals=sig.werte;
tomwalters@0: nr_bin=time2bin(sig,where);
tomwalters@0: nr_values=getnrpoints(sig);
tomwalters@0: howmuchdecrease=vals(nr_bin)*(1-howmuch);   % value at the desired point
tomwalters@0: val=0;
tomwalters@0: hoch=0;
tomwalters@0: breit=0;
tomwalters@0: widthvals(1)=-inf;
tomwalters@0: widthvals(2)=inf;
tomwalters@0: 
tomwalters@0: int_time_up=nr_values+1;
tomwalters@0: for i=nr_bin:nr_values
tomwalters@0:     if vals(i)< howmuchdecrease
tomwalters@0:         int_time_up=i;
tomwalters@0: 		widthvals(1)=i;
tomwalters@0:         break;
tomwalters@0:     end
tomwalters@0: end
tomwalters@0: 
tomwalters@0: int_time_down=0;
tomwalters@0: for i=nr_bin:-1:1
tomwalters@0:     if vals(i)< howmuchdecrease
tomwalters@0:         int_time_down=i;
tomwalters@0: 		widthvals(2)=i;
tomwalters@0:         break;
tomwalters@0:     end
tomwalters@0: end
tomwalters@0: 
tomwalters@0: if int_time_down==0 | int_time_up==nr_values
tomwalters@0:     hoch=vals(nr_bin);
tomwalters@0:     breit=1000000;
tomwalters@0:     val=hoch/breit;
tomwalters@0: 	widthvals(1)=0;	widthvals(2)=0;
tomwalters@0:     return;
tomwalters@0: end
tomwalters@0: 
tomwalters@0: time_up=bin2time(sig,int_time_up);
tomwalters@0: time_down=bin2time(sig,int_time_down);
tomwalters@0: 
tomwalters@0: hoch=vals(nr_bin);
tomwalters@0: breit=time_up-time_down;
tomwalters@0: if breit>0
tomwalters@0: 	val=hoch/breit;	
tomwalters@0: else
tomwalters@0: 	vals=0;
tomwalters@0: end
tomwalters@0: 
tomwalters@0: 
tomwalters@0: 
tomwalters@0: