function myemd(x,fs)
[imf] = emd(x);
[A,f,tt] = hhspectrum(imf);
[im] = toimage(A,f,tt);

partial = sum(im,2);

l = length(partial);
n = floor(l*6/fs*2);

semilogy(linspace(.5*fs,0,l), partial);
title('EMD');
xlabel('Frequency (Hz)');
ylabel('Power');
axis([0 6 0 10*mean(partial(l-n:l))]);
disp_hhs(im(l-n:l,:));