Model Attributes

Specify and query model characteristics such as coefficients, labels, and units

Model properties are the data fields that store all information about a dynamic system model. Data stored in model properties includes model dynamics, such as transfer-function coefficients, state-space matrices, and time delays. Access these properties to extract or change data about model dynamics. You can also specify metadata about the model such as input and output names or units.

Functions

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Access Model Properties

`get`	Access model property values
`set`	Set or modify model properties

Access Dynamical Data

`tfdata`	Access transfer function data
`zpkdata`	Access zero-pole-gain data
`ssdata`	Access state-space model data
`frdata`	Access data for frequency response data (FRD) object
`piddata`	Access coefficients of parallel-form PID controller
`pidstddata`	Access coefficients of standard-form PID controller
`piddata2`	Access coefficients of parallel-form 2-DOF PID controller
`pidstddata2`	Access coefficients of standard-form 2-DOF PID controller
`dssdata`	Extract descriptor state-space data

Change Model Units

`chgFreqUnit`	Change frequency units of frequency-response data model
`chgTimeUnit`	Change time units of dynamic system

Query Model Characteristics

`isct`	Determine if dynamic system model is in continuous time
`isdt`	Determine if dynamic system model is in discrete time
`isempty`	Determine whether dynamic system model is empty
`isfinite`	Determine if model has finite coefficients
`isParametric`	Determine if model has tunable parameters
`isproper`	Determine if dynamic system model is proper
`isreal`	Determine if model has real-valued coefficients
`issiso`	Determine if dynamic system model is single-input/single-output (SISO)
`isstable`	Determine if dynamic system model is stable
`isstatic`	Determine if model is static or dynamic
`order`	Query model order
`ndims`	Query number of dimensions of dynamic system model or model array
`size`	Query output/input/array dimensions of input–output model and number of frequencies of FRD model
`findop`	Compute operating condition from specifications (Since R2023b)

Other Utilities

frdfun Apply a function to the frequency response value at each frequency of an frd model object (Since R2020a)

Topics

Accessing and Modifying the Model Data
This example shows how to access or edit parameter values and metadata in LTI objects.
Store and Retrieve Model Data
Extract and change model properties such as model dynamics, sample time, and channel names.
Extract Model Coefficients
Extract model coefficients such as transfer function numerator and denominator coefficients, state-space matrices, and PID gains.
Attach Metadata to Models
Specify additional model properties such as time units, input and output names, and input and output groups.
Query Model Characteristics
Query dynamic-system model characteristics such as stability, time domain, and number of inputs and outputs.
Customize Model Display
Configure how transfer functions are displayed in the MATLAB^® command window.