Dawn@4: function E = func_GetEnergy(y, F0, Fs, variables)
Dawn@4: % E = func_GetEnergy(y, F0, Fs, variables)
Dawn@4: % Input:  y, Fs - from wavread
Dawn@4: %         F0 - vector of fundamental frequencies
Dawn@4: %         variables - global settings
Dawn@4: % Output: Energy vector
Dawn@4: % Notes:  Calculates the energy, normalized for F0. This is done by using a
Dawn@4: % variable length window consisting of 5 pitch periods, according to the F0
Dawn@4: % at a particular point in time.
Dawn@4: %
Dawn@4: % Author: Yen-Liang Shue, Speech Processing and Auditory Perception Laboratory, UCLA
Dawn@4: % Copyright UCLA SPAPL 2009
Dawn@4: 
Dawn@4: N_periods = variables.Nperiods_EC;
Dawn@4: sampleshift = (Fs / 1000 * variables.frameshift);
Dawn@4: 
Dawn@4: E = zeros(length(F0), 1) * NaN;
Dawn@4: 
Dawn@4: for k=1:length(F0)
Dawn@4:   ks = round(k * sampleshift);
Dawn@4:   
Dawn@4:   if (ks <= 0 || ks > length(y))
Dawn@4:       continue;
Dawn@4:   end
Dawn@4:  
Dawn@4:   F0_curr = F0(k);
Dawn@4:   
Dawn@4:   if (isnan(F0_curr))
Dawn@4:       continue;
Dawn@4:   end
Dawn@4:   
Dawn@4:   N0_curr = Fs/F0_curr;
Dawn@4:   
Dawn@4:   ystart = round(ks - N_periods/2 * N0_curr);
Dawn@4:   yend = round(ks + N_periods/2 * N0_curr) - 1;
Dawn@4:   
Dawn@4:   if (ystart <= 0)
Dawn@4:     continue;
Dawn@4:   end
Dawn@4:   
Dawn@4:   if (yend > length(y))
Dawn@4:     continue;
Dawn@4:   end
Dawn@4:   
Dawn@4:   yseg = y(ystart:yend);
Dawn@4:   
Dawn@4:   E(k) = sum(yseg .^ 2);
Dawn@4:     
Dawn@4: end
Dawn@4: