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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getAccess model property values
setSet or modify model properties
tfdataAccess transfer function data
zpkdataAccess zero-pole-gain data
ssdataAccess state-space model data
frdataAccess data for frequency response data (FRD) object
piddataAccess coefficients of parallel-form PID controller
pidstddataAccess coefficients of standard-form PID controller
piddata2Access coefficients of parallel-form 2-DOF PID controller
pidstddata2Access coefficients of standard-form 2-DOF PID controller
dssdataExtract descriptor state-space data
chgFreqUnitChange frequency units of frequency-response data model
chgTimeUnitChange time units of dynamic system
isctDetermine if dynamic system model is in continuous time
isdtDetermine if dynamic system model is in discrete time
isemptyDetermine whether dynamic system model is empty
isfiniteDetermine if model has finite coefficients
isParametricDetermine if model has tunable parameters
isproperDetermine if dynamic system model is proper
isrealDetermine if model has real-valued coefficients
issisoDetermine if dynamic system model is single-input/single-output (SISO)
isstableDetermine whether system is stable
isstaticDetermine if model is static or dynamic
orderQuery model order
ndimsQuery number of dimensions of dynamic system model or model array
sizeQuery output/input/array dimensions of input–output model and number of frequencies of FRD model

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.