title: How to calculate a Infinity norm (H) of a dynamic system?
body: <p>I am trying to get the Infinity Norm (H) of two dynamic systems: the first is a noncontrolled system and the second is a controlled system.
  I have plotted the time and frequency response of the two models on Jupyter Notebook, as follows:</p>
  <p><a href="https://i.stack.imgur.com/DTDXV.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DTDXV.png" alt="enter image description here" /></a>
  <a href="https://i.stack.imgur.com/fuy0U.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fuy0U.png" alt="enter image description here" /></a></p>
  <p>Nevertheless, I would like to calculate the infinity_norm (H_infinity) and the H2_norm. Does anyone know how can I do it? Or someone can suggest me any command on python to do that?
  I thought that the H_infinity norm is the peak of the spectrum, but I am not sure.</p>