Creating poles and zeros


Poles and zeros are treated the same with regards creation, so we will look here at poles only. The meaning of a pole and a zero only becomes important when creating a pole/zero model.

Poles are specified by in the LTPDA Toolbox by a frequency, f, and (optionally) a quality factor, Q, or by a complex number.

The following code fragment creates a real pole at 1Hz:

  	>> pz(1)
------ pz/1 -------
      f: 1
      q: NaN
     ri: -6.28318530717959
version: $Id: pzmodel_pz_content.html,v 1.3 2009/02/18 12:15:16 hewitson Exp $
-------------------
  

To create a complex pole, you can specify a quality factor. For example,

   >> pz(1,4)
------ pz/1 -------
      f: 1
      q: 4
     ri: [0.785398163397448+i*6.23390466154956;0.785398163397448-i*6.23390466154956]
version: $Id: pzmodel_pz_content.html,v 1.3 2009/02/18 12:15:16 hewitson Exp $
-------------------
  

This creates a complex pole at 1Hz with a Q of 4. You can also see that the complex representation is also shown, but only one part of the conjugate pair.




©LTP Team