Main Content

Represent Data

Measure or generate data, import in GUI or represent using data objects, manipulate complex data


iddataInput-output data and its properties for system identification in the time or frequency domain
idfrdFrequency response data or model
idinputGenerate input signals
simSimulate response of identified model
sizeQuery output/input/array dimensions of input–output model and number of frequencies of FRD model
midprefsSpecify location for file containing System Identification app startup information
simOptionsOption set for sim


Iddata SinkExport simulation data as iddata object to MATLAB workspace
Iddata SourceImport time-domain data stored in iddata object in MATLAB workspace

Examples and How To

Import Time-Domain Data into the App

Import time-domain data into the System Identification app

Import Frequency-Domain Data into the App

Import frequency-domain input-output data and frequency-response data into the System Identification app.

Import Data Objects into the App

Import iddata and idfrd data objects.

Generate Data Using Simulation

Creating input data with specific characteristics and simulating the output data from a model.


Representing Data in MATLAB Workspace

Represent time-domain, time-series, and frequency-domain data.

Requirements on Data Sampling

The toolbox provides limited support for nonuniformly sampled data.

Specifying the Data Sample Time

Specify time between successive data samples.

Managing Data in the App

You can get information about each data set in the System Identification app by right-clicking the corresponding data icon.

Representing Time- and Frequency-Domain Data Using iddata Objects

Using the iddata constructor to represent time-domain and frequency-domain data and working with iddata objects.

Managing iddata Objects

The iddata object stores time-domain data or frequency-domain data and has several properties that specify the time or frequency values.

Representing Frequency-Response Data Using idfrd Objects

Using the idfrd constructor to represent frequency-response data and working with idfrd objects.

Manipulating Complex-Valued Data

Supported operations and limitations for handling complex data and commands for manipulating complex signals.