Closed
Description
Given the transfer function
G = 1/s^3
We should see a constant negative phase of -270°, which is confirmed in matlab
However, both control.bode and control.matlab.bode give 90° instead of -270°. Although technically the same value, it does get confusing.
import control
import control.matlab
s = control.tf('s')
G = 1/s**3
control.bode(G);
control.matlab.bode(G);
What i've tried so far
- using different transfer functions (1/s^4 or 1/s^2 * 1/(s+10))
- specifying "omega" with a frequency range (as suggested here : https://ch.mathworks.com/matlabcentral/answers/99531-why-is-the-phase-that-is-returned-by-the-bode-function-wrapping-in-the-control-system-toolbox-5-1-r )
- extending the "omega" range
Is it possible to get the "absolute" phase of the transfer function ? If not, i would suggest that control.matlab.bode be corrected as to reflect the behavior of matlab's bode
Thanks for your help !