Simulation Data Inspector - Inspect and compare data and simulation results to validate and iterate model

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Inspect and compare data and simulation results to validate and iterate model designs

Description

The Simulation Data Inspector visualizes and compares multiple kinds of data.

Using the Simulation Data Inspector, you can inspect and compare time series data at multiple stages of your workflow. This example workflow shows how the Simulation Data Inspector supports all stages of the design cycle:

  1. View Simulation Data in Simulation Data Inspector or Import Data from Workspace or File into Simulation Data Inspector
    Run a simulation in a model configured to log data to the Simulation Data Inspector, or import data from the workspace or a file. You can view and verify model input data or inspect logged simulation data while iteratively modifying your model diagram, parameter values, or model configuration. For more information about logging simulation data, seeSave Simulation Data.
  2. Inspect Simulation Data
    Plot signals on multiple subplots, zoom in and out on specified plot axes, and use data cursors to understand and evaluate the data. You can choose from several visualizations, such as time, array, map, sparklines, and XY plots. For more information on presenting data effectively, see Create Plots Using the Simulation Data Inspector.
  3. Compare Simulation Data
    Compare individual signals or simulation runs and analyze your comparison results with relative, absolute, and time tolerances. The compare tools in the Simulation Data Inspector facilitate iterative design and allow you to highlight signals that do not meet your tolerance requirements. For more information about the comparison operation, see How the Simulation Data Inspector Compares Data.
  4. Save and Share Simulation Data Inspector Data and Views
    Share your findings with others by saving Simulation Data Inspector data and views.

You can also harness the capabilities of the Simulation Data Inspector from the command line. For more information, see Inspect and Compare Data Programmatically.

The Inspect pane of the Simulation Data Inspector shows three subplots. The subplots show time plots of data gathered from three runs of the model sldemo_autotrans. The first subplot shows the EngineRPM signals from all three runs. The second subplot shows the ShiftLogic signals from all three runs. The third subplot shows the VehicleSpeed signal from all three runs.

Open the Simulation Data Inspector

Examples

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Create a run, add data to it, and then view the data in 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(0,20,100);

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

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

Create Run and Add Data

Use the Simulink.sdi.view function to open the Simulation Data Inspector.

To import data into the Simulation Data Inspector from the workspace, create a Simulink.sdi.Run object using the Simulink.sdi.Run.create function. Add information about the run to its metadata 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";

Use the add function to add the data you created in the workspace to the empty run.

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

Plot Data in Simulation Data Inspector

Use the getSignalByIndex function to access Simulink.sdi.Signal objects that contain the signal data. 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. 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 = "--";

Use the Simulink.sdi.setSubPlotLayout function to configure a 2-by-1 subplot layout in the Simulation Data Inspector plotting area. Then, use the plotOnSubplot function to plot the sine signal on the top subplot and the cosine signal on the lower subplot.

Simulink.sdi.setSubPlotLayout(2,1);

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

The sine wave and cosine wave signals are plotted in the Simulation Data Inspector. Two subplots align vertically. In the upper subplot, the Sine, T=5 signal is plotted in blue with a dash-dotted line style. In the lower subplot, Cosine, T=8 signal is plotted in red with a dashed line style.

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")

You can use the Simulink.sdi.plot function to plot simulation results in the Simulation Data Inspector. Open the model vdp, which models the second-order Van der Pol differential equation. For more information about the model, see Van der Pol Oscillator.

mdl = "vdp"; open_system(mdl)

The vdp model

Simulate the model. The model logs two signals: x1 and x2. Simulation results are stored in a single SimulationOutput object named out.

Use the Simulink.sdi.plot function to open the Simulation Data Inspector and plot the results.

Simulation results are plotted on two vertically aligned subplots in the Simulation Data Inspector. The x1 signal is plotted in the upper subplot. The x2 signal is plotted in the lower subplot.

You can use the Simulation Data Inspector programmatic interface to modify a parameter for the same signal in multiple runs. This example adds an absolute tolerance of 0.1 to a signal in all four runs of data.

First, clear the workspace and load the Simulation Data Inspector session with the data. The session includes logged data from four simulations of a Simulink® model of a longitudinal controller for an aircraft.

Simulink.sdi.clear Simulink.sdi.load('AircraftExample.mldatx');

Use the Simulink.sdi.getRunCount function to get the number of runs in the Simulation Data Inspector. You can use this number as the index for a for loop that operates on each run.

count = Simulink.sdi.getRunCount;

Then, use a for loop to assign the absolute tolerance of 0.1 to the first signal in each run.

for a = 1:count runID = Simulink.sdi.getRunIDByIndex(a); aircraftRun = Simulink.sdi.getRun(runID); sig = getSignalByIndex(aircraftRun,1); sig.AbsTol = 0.1; end

Programmatic Use

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Simulink.sdi.view opens the Simulation Data Inspector from the MATLAB command line.

Version History

Introduced in R2010b

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To avoid scalability issues, data is no longer streamed to XY visualizations in the Simulation Data Inspector, Record block, or XY Graph block.