title: How to programatically find the magnitude and frequency for a given phase in a bode plot?
body: <p>If I have a Plant let's say </p>
  
  <blockquote>
    <p>Gp(s) = 1/(s+1)</p>
  </blockquote>
  
  <p>I can find the Phase Margin</p>
  
  <p>Using MATLAB commands</p>
  
  <pre><code>Gp = tf([1],[1 1]);
  [G P] = margin(Gp);
  </code></pre>
  
  <p>My question is what if I want to know the phase over frequency in a specific Gain Over Frequency. How do I find it without looking to bode plot?</p>
  
  <p>Usually I find it by the command bode(Gp) and move the mouse over the specific gain that I want to know the phase margin on it.</p>
  
  <p>For my previous example The Gain Over Frequency is 0.363 at -20 Phase Over Frequency.</p>
  
  <p>How do I write it as a command not looking in the bode diagram?</p>
  
  <p>Thanks in advance</p>