% Nise, N.S.
% Control Systems Engineering, 6th ed.
% John Wiley & Sons, Hoboken, NJ, 07030
% Control Systems Engineering Toolbox Version 6.0
% Copyright 2011 by John Wiley & Sons, Inc.
% (ch2p11):LTI models can also be converted between polynomial and factored forms.
% MATLAB commands tf and zpk are also used for the conversion between
% LTI models. If a transfer function, Fzpk(s), is expressed as factors in the
% numerator and denominator, then tf(Fzpk) converts Fzpk(s) to a transfer function
% expressed as coefficients in the numerator and denominator. Similarly, if a
% transfer function, Ftf(s) is expressed as coefficients in the numerator and
% denominator, then zpk(Ftf) converts Ftf(s) to a transfer function expressed as
% factors in the numerator and denominator. The following example demonstrates
% the concepts.
'(ch2p11)' % Display label.
'Fzpk1(s)' % Display label.
Fzpk1=zpk([-2 -4],[0 -3 -5],10) % Form Fzpk1(s)=
'Ftf1' % Display label.
Ftf1=tf(Fzpk1) % Convert Fzpk1(s) to
% coefficients form.
'Ftf2' % Display label.
Ftf2=tf([10 40 60],[1 4 5 7]) % Form Ftf2(s)=
'Fzpk2' % Display label.
Fzpk2=zpk(Ftf2) % Convert Ftf2(s) to
% factored form.