Inspect Data Programmatically

R2026b

You can harness the capabilities of the Simulation Data Inspector programmatically from the MATLAB^® command line.

The Simulation Data Inspector organizes data in runs and signals, assigning a unique numeric identifier to each run and signal. The Simulink.sdi.Run and Simulink.sdi.Signal objects allow you to access to your data and view and modify run and signal metadata. When you interact with the Simulation Data Inspector programmatically, some functions require Signal or Run objects as inputs, while others use signal or run IDs. This table lists some ways to access these objects and IDs.

Action	Function	Input Required
Access run ID	Simulink.sdi.getAllRunIDs	None
	Simulink.sdi.getRunIDByIndex	Index of run in Simulation Data Inspector repository
Access Simulink.sdi.Run object	Simulink.sdi.Run.getLatest	None
	Simulink.sdi.getCurrentSimulationRun	Model name
	Simulink.sdi.getRun	Run ID
Access signal ID	getAllSignalIDs	Run object
	getSignalIDByIndex	Run object and index of signal in the run
	getSignalIDsByName	Run object and signal name
Access Simulink.sdi.Signal object	getAllSignals	Run object
	getSignalByIndex	Run object and index of signal in the run
	getSignalsByName	Run object and signal name
	Simulink.sdi.getSignal	Signal ID

You can modify the Simulation Data Inspector preferences using functions like Simulink.sdi.setSubPlotLayout, Simulink.sdi.setRunNamingRule, and Simulink.sdi.setVisualization. To restore the Simulation Data Inspector default settings, use Simulink.sdi.clearPreferences.

Create Run and View Data

Create a run, add data to it, and then view the data in the active tab of the Simulation Data Inspector.

Create Data for Run

Create two timeseries objects to contain data for a sine signal and a cosine signal. Give each timeseries object a descriptive name.

time = linspace(0,20,101);

sine_vals = sin(2*pi/5*time);
sine_ts = timeseries(sine_vals,time);
sine_ts.Name = "Sine, T=5";

cos_vals = cos(2*pi/8*time);
cos_ts = timeseries(cos_vals,time);
cos_ts.Name = "Cosine, T=8";

Create Run and Add Data

To open the Simulation Data Inspector, use Simulink.sdi.view.

Simulink.sdi.view

To import data into the Simulation Data Inspector from the workspace, create a Simulink.sdi.Run object using Simulink.sdi.Run.create. Add metadata information using the Name and Description properties of the Run object.

sinusoidsRun = Simulink.sdi.Run.create;
sinusoidsRun.Name = "Sinusoids";
sinusoidsRun.Description = "Sine and cosine signals with different frequencies";

Add the data you created in the workspace to the empty run.

add(sinusoidsRun,"vars",sine_ts,cos_ts);

 0.091530s wall, 0.156250s user + 0.031250s system = 0.187500s CPU (204.9%)

Plot Data in Simulation Data Inspector

To access the Simulink.sdi.Signal object corresponding to each signal, use getSignalByIndex. You can use the Simulink.sdi.Signal object properties to specify the line style and color for the signal and plot the signal in the Simulation Data Inspector. For example, specify the LineColor and LineDashed properties for each signal.

sine_sig = getSignalByIndex(sinusoidsRun,1);
sine_sig.LineColor = [0 0 1];
sine_sig.LineDashed = "-.";

cos_sig = sinusoidsRun.getSignalByIndex(2);
cos_sig.LineColor = [1 0 0];
cos_sig.LineDashed = "--";

To configure a 2-by-1 subplot layout in the active tab of the Simulation Data Inspector plotting area, use Simulink.sdi.setSubPlotLayout. To plot the sine signal on the upper subplot and the cosine signal on the lower subplot, use plotOnSubPlot.

Simulink.sdi.setSubPlotLayout(2,1);

plotOnSubPlot(sine_sig,1,1,true);
plotOnSubPlot(cos_sig,2,1,true);

Inspect Data Using Cursors

To access the value of a signal at a specific time, you can add a cursor to the plot. For example, the Sine signal appears to have a local maximum at about 6 seconds. Add one cursor to the plot and observe the signal value at 6 seconds.

Simulink.sdi.setNumCursors(1)
Simulink.sdi.setCursorPositions("left",6)

To measure the time difference between two points or extract descriptive statistics within the defined interval, add two cursors.

Simulink.sdi.setNumCursors(2)
Simulink.sdi.setCursorPositions("left",5,"right",7)

Determine the local maximum sample value in the Sine signal between the cursors using the max function.

[t1,t2] = Simulink.sdi.getCursorPositions;
localMax = max(sine_sig,t1,t2)

localMax = 
0.9980

Close Simulation Data Inspector and Save Data

When you finish inspecting the plotted signal data, you can close the Simulation Data Inspector and save the session to an MLDATX file.

Simulink.sdi.close("sinusoids.mldatx")