User`s guide

d2d
11-51
11d2d
Purpose Resample discrete-time LTI models or add input delays
Syntax sys1 = d2d(sys,Ts)
Description sys1 = d2d(sys,Ts) resamples the discrete-time LTI model sys to produce an
equivalentdiscrete-time model
sys1 withthenewsampletimeTs (inseconds).
The resampling assumes zero-order hold on the inputs and is equivalent to
consecutive
d2c and c2d conversions.
sys1 = c2d(d2c(sys),Ts)
Example Consider the zero-pole-gain model
with sample time 0.1 second. You can resample this model at 0.05 second by
typing
H = zpk(0.7,0.5,1,0.1)
H2 = d2d(H,0.05)
Zero/pole/gain:
(z–0.8243)
----------
(z–0.7071)
Sampling time: 0.05
Notethatthe inverseresamplingoperation,performed bytypingd2d(H2,0.1),
yields back the initial model .
Zero/pole/gain:
(z–0.7)
-------
(z–0.5)
Sampling time: 0.1
See Also c2d Continuous- to discrete-time conversion
d2c Discrete- to continuous-time conversion
Hz()
z 0.7
–
z 0.5–
-----------------=
Hz
()