Specifications

frd
16-80
16frd
Purpose Create a frequency response data (FRD) object or convert another model type
to an FRD model
Syntax sys = frd(response,frequency)
sys = frd(response,frequency,Ts)
sys = frd
sys = frd(response,frequency,ltisys)
sysfrd = frd(sys,frequency)
sysfrd = frd(sys,frequency,'Units',units)
Description sys = frd(response,frequency) creates an FRD model sys from the
frequency response data stored in the multidimensional array
response.The
vector
frequency represents the underlying frequencies for the frequency
response data. See Table 16-16, Data Format for the Argument response in
FRD Models.
sys = frd(response,frequency,Ts) creates a discrete-time FRD model sys
with scalar sample time Ts.SetTs = -1 to create a discrete-time FRD model
without specifying the sample time.
sys = frd creates an empty FRD model.
The input argument list for any of these syntaxes can be followed by property
name/property value pairs of the form
'PropertyName',PropertyValue
You can use these extra arguments to set thevarious properties of FRD models
(seethe
set command, orLTIPropertiesand Model-SpecificProperties).These
properties include
'Units'. The default units for FRD models are in 'rad/s'.
To force an FRD model
sys to inherit all of its generic LTI properties from any
existing LTI model
refsys, use the syntax
sys = frd(response,frequency,ltisys)
sysfrd = frd(sys,frequency)
converts a TF, SS, or ZPK model to an FRD
model. The frequency response is computed at the frequencies provided by the
vector
frequency.