User`s guide

Transforming Between Time- and Frequency-Do main Data
Original Data
Format
To Time Domain
(iddata object)
To Frequency
Domain
(iddata object)
To Frequency
Function
(idfrd object)
Frequency
Domain
(
iddata object)
Yes, using
ifft.
No.
Yes, using etfe,
spa,orspafdr.
Frequency
Function
(
idfrd object)
No.
Yes. Calculati
on
creates
frequency-do
main
iddata object
that has the
same ratio
between outp
ut
and input as t
he
original
id
frd
object.
Yes. Calculate
s
a frequency
function with
different
resolution
(number and
spacing of
frequencies
)
using
spafd
r
.
Transform
ing Between Time and Frequency Domain
The iddata object stores time-domain or frequency-domain data. The
following table summarizes the commands f or transforming data between
time and frequency domains.
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