annotate genbh92lobe.m @ 13:844d341cf643 tip

Back up before ISMIR

function y = genbh92lobe(x) 
% Calculate transform of the Blackman-Harris 92dB window 
% x: bin positions to compute (real values), y: transform values 
N = 512; 
f = x*pi*2/N;    % frequency sampling 
df = 2*pi/N; 
y = zeros(size(x));   % initialize window 
consts = [.35875, .48829, .14128, .01168];      % window constants 
for m=0:3 
    y = y + consts(m+1)/2*(D(f-df*m,N)+D(f+df*m,N));   % sum Dirichlet kernels 
end 
y = y/N/consts(1);  % normalize 
end 
function y = D(x,N) 
% Calculate rectangular window transform (Dirichlet kernel) 
y = sin(N*x/2)./sin(x/2); 
y(find(y~=y))=N;    % avoid NaN if x==0 
end