The freqz function appears to return the frequency values and the frequency response backwards. Like it is supposed to return in the order (h,w) but it actually returns in the order (w,h).<div><br></div><div>This can even be seen in the documentation here:</div>

<div><a href="http://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.freqz.html">http://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.freqz.html</a></div><div><br></div><div><br></div>