User`s guide

1 Quick Start
1-4
To create discrete-time models, append the sample time Ts to the previous
calling sequences.
sys = tf(num,den,Ts)
sys = zpk(z,p,k,Ts)
sys = ss(a,b,c,d,Ts)
sys = frd(response,frequency,Ts)
For more information, see “Discrete-Time Models” on page 2-20.
For example, type
sys = zpk(0.5,[–0.1 0.3],1,0.05)
and MATLAB responds with
Zero/pole/gain:
(z–0.5)
---------------
(z+0.1) (z–0.3)
Sampling time: 0.05
You c an retrieve the model data st ored in the LTI o bject sys with the following
commands (see “Data Retrieval” on page 2-24 for more information).
[num,den,Ts] = tfdata(sys)
[z,p,k,Ts] = zpkdata(sys)
[a,b,c,d,Ts] = ssdata(sys)
[response,frequency,Ts] = frdata(sys)
Alternately, you can access this data by direct structure-like referencing (see
“Direct Property Referencing” on page 2-33 for more information), as in this
example.
sys.num
sys.a
sys.Ts
MIMO Systems
You can also create multi-input/multi-output (MIMO) models, including
arbitrary MIMO transfer functions and zero/pole/gain models. MIMO transfer
functions are arrays of single-input/single-output (SISO) transfer functions