function bodehz(h, w)
% same as bode, but horizontal axis is [Hz] instead of [rad/s]
[a, b] = tfdata(h);
as = polyscale(a{1}, 0.5/pi);
bs = polyscale(b{1}, 0.5/pi);
hs = tf(as, bs);
if nargin > 1
    bode(hs, w/2/pi);
else
    bode(hs);
end
xlabel('Frequency [Hz]');
