MATLAB: How to extract phase information from freqs

MATLAB

I'm plotting using this:
    freqs(butter_tf_num,butter_tf_den, scale)
But I want to adjust the X axis to another unit and set limits. So I do:
[H,W] = freqs(butter_tf_num,butter_tf_den, scale);
Freq_Hz = W(:)/2/pi;
subplot(3,2,1)
% Magnitude
plot(Freq_Hz, abs(H))
subplot(3,2,2)
% Phase
plot(Freq_Hz, atand(imag(H)./real(H)))
axis([600 1000 -200 200])
But the result is different… Why?

Best Answer

Instead of
   atand(imag(H)./real(H))
please try using
   angle(H)*180/pi
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