Converting models between different representations

The different constructors from each transfer function representations accept as an input a model from a another representation so that they can all be converted between the different representations. In the current LTPDA version, this applies for pole/zero model and rational representation. Following versions will cover the partial fraction representation. This is shown in the following transformation table:

Pole/zero model TF

From pzmodel to rational

You can transform a pzmodel into a rational by typing:
    >> rat   = rational(pzmodel)

From rational to pzmodel

You can transform a rational into a pzmodel by typing:
    >> rat   = pzmodel(rational)


To translate from rational to pzmodel representation we need to compute the roots of a polynomial and the inverse operation is performed going from pzmodel to rational. More information about the algorithm used can be found in MATLAB's functions poly and roots.

©LTP Team