title: Lowpass Filter in python
body: <p>I am trying to convert a Matlab code to Python. I want to implement <code>fdesign.lowpass()</code> of Matlab in Python. What will be the exact substitute of this Matlab code using <code>scipy.signal.firwin()</code>:</p>
  
  <pre><code>demod_1_a = mod_noisy * 2.*cos(2*pi*Fc*t+phi);
  d = fdesign.lowpass('N,Fc', 10, 40, 1600);
  Hd = design(d);
  y = filter(Hd, demod_1_a);
  </code></pre>