Inspect Simulation Data

You can use the Simulation Data Inspector to view and inspect signals from simulations or imported data. The Simulation Data Inspector provides a comprehensive view of your data by allowing you to group data from multiple simulations and sources on multiple subplots. You can zoom and pan within plots and use data cursors for close examination of signal values, and you can replay data to analyze signal relationships.

This example shows you how to view and inspect signal data from the slexAircraftExample model using the Simulation Data Inspector.

Configure Signals for Logging

This example uses signal logging to send data to the Simulation Data Inspector. You can also import signal data from the base workspace or a CSV, MDF, Microsoft® Excel®, or MAT-file. For more information, see View Data with the Simulation Data Inspector.

Open the slexAircraftExample model, mark several signals for logging, and run a simulation.

  1. To open the model, enter slexAircraftExample in the MATLAB® Command Window.

  2. To log the q, rad/sec, the Stick, and the alpha, rad signals, select the signals in the model. Then, click Log Signals.

    The logging badge appears above each signal marked for logging.

  3. Double-click the Pilot block. Set Wave form to sine, and click OK.

  4. In the Simulink® Editor, click the Data Inspector button to open the Simulation Data Inspector.

  5. Simulate the model. The simulation run appears in the Simulation Data Inspector.

    By default, the Inspect pane lists all logged signals in rows, organized by simulation run. You can expand or collapse any of the runs to view the signals in a run. For more information on signal grouping, see Organize Your Simulation Data Inspector Workspace.

View Signals

To select signals you want to plot, use the check boxes next to the signals in the navigation pane. Select the check boxes next to the q, rad/sec, Stick, and alpha, rad signals. When the signal you want to plot is easier to find in your model, you can click the logging badge for the signal to plot it in the Simulation Data Inspector.

You can also use signal browsing mode to quickly view all the signals in your run on Time Plot visualizations. For more information about how to enable and use Browse Mode, see Visualize Many Logged Signals.

View Signals on Multiple Plots

You can use subplot layouts to view groups of signals on different subplots. For example, you can group the same signal from different simulation runs or group signals that have a similar range of values.

  1. In the model, double-click the Pilot block. Set Wave form to square, and click OK.

  2. Simulate the model.

  3. By default, the Simulation Data Inspector automatically moves prior runs into the Archive and transfers the view to the current run. Drag Run 1 from the Archive into the work area.

  4. Click the Layout button and select the 2×1 plot layout.

  5. Click the lower subplot in the viewing area. In the Inspect pane, select the check boxes for the q, rad/sec, Stick, and alpha, rad signals under Run 1.

    The check boxes in the Inspect pane indicate the signals plotted in the selected subplot, outlined in blue.

You can also move signals graphically, rather than using the check boxes. Click and drag the signal from the Inspect pane or another subplot to the subplot where you want to plot it.

For more information on working with plots, see Create Plots Using the Simulation Data Inspector.

Zoom, Pan, and Resize Plots

You can closely inspect signals in a larger viewing area using the Maximize and Full Screen options on the toolbar above the viewing area.

  • — Click the Maximize button to expand the active subplot to occupy the entire graphical viewing area.

  • — Click the Full Screen button to view your entire layout using your whole screen. The Simulation Data Inspector automatically collapses the navigation pane so your layout is as large as possible.

You can zoom and pan within subplots that use a time plot visualization to inspect signal values and the relationships between signals. The zoom and pan controls in the Simulation Data Inspector are on the toolstrip above the graphical viewing area. Each icon allows you to control the aspects of the plot using your mouse.

  • You can select the zoom action for the zoom button from the drop-down.

    • When you select the zoom-in option, all the mouse actions zoom in on both the y- and t-axes. You can click the graphical viewing area to zoom in a fixed amount on both axes. You can also click and drag to select an area to define the y- and t-axes. Scrolling with the mouse wheel zooms in and out on both axes.

    • Click the zoom-out option to zoom out a fixed amount.

    • The t-axis zoom option makes all the mouse actions zoom on the t-axis. You can click the graphical viewing area to zoom in a fixed amount. You can click and drag the graphical viewing area to select a portion of the plot as the limits for the t-axis. Scrolling with the mouse wheel zooms in and out on the t-axis.

    • When you select the y-axis zoom option, all the mouse actions zoom on the y-axis. You can click in the graphical viewing area to zoom in a fixed amount. You can also click and drag to select a portion of the plot as the limits for the y-axis. Scrolling with the mouse wheel zooms in and out on the y-axis.

  • With the mouse pointer selected, you can select signals by clicking them and pan by clicking anywhere on the plot and dragging the mouse.

  • Click the fit-to-view option to scale the axes to accommodate your plotted data.

Linked Subplots

Subplots are linked by default. Linked plots have a synchronized response when you:

  • Click a plot and drag to pan.

  • Perform any zoom operation.

  • Fit to view.

  • Adjust T-Axis limits.

To inspect data independently in a subplot, you can unlink the subplot.

  1. Select the subplot you want to unlink.

  2. Click the Visualization Settings button in the upper right of the viewing area.

  3. In the Limits section, clear the Link Subplot option.

    The broken link symbol appears on the unlinked subplot.

Inspect Simulation Data Using Cursors

In the Simulation Data Inspector, you can inspect signals using data cursors. You can use one or two cursors to inspect your data. To add two cursors, select Two Cursors from the Show/hide data cursors drop-down.

With two cursors, three time values are displayed: the time corresponding to each cursor position and the time spanned by the cursors. You can move the two cursors together by dragging the span label between the two cursors. You can also set the span by typing the desired value into the label field.

Practice inspecting data with cursors using one cursor.

  1. Select One Cursor from the Show/hide data cursors drop-down.

  2. Drag the data cursor left or right to a point of interest. You can also use the arrow keys to move the data cursor from sample to sample.

    To inspect the data at a specific point in time, click the cursor time field and enter the desired time value, for example 40.33.

    If the signal does not have a sample at the point of interest, the Simulation Data Inspector interpolates the value for the indicated time. An asterisk in the data cursor label indicates that the displayed value is interpolated. For information regarding interpolation methods, see Interpolation.

  3. When you have finished inspecting the data, click the cursor button to remove the cursor from the viewing area.

Replay Data

You can replay data in the Simulation Data Inspector to inspect signal value changes and relationships between signals. Replaying data in the Simulation Data Inspector has no effect on any models or simulations. To replay data, first show the replay controls by clicking the Show/hide replay controls button. Then, press the Replay button.

The Simulation Data Inspector synchronously sweeps a cursor displaying the signal value across all subplots in the view. By default, data replays at a rate of one second per second, which means that replaying one second of data takes one second of clock time. You can adjust the replay speed using the arrows on either side of the label or by clicking the label to type the desired speed. You can also pause the replay and use the Step forward and Step backward buttons to inspect signal values, sample by sample. For a detailed example, see Replay Data in the Simulation Data Inspector.

Inspect Metadata

The Simulation Data Inspector allows you to view run and signal metadata. You can view signal metadata in the Properties pane or in the table of signals under each run. You can view run data only in the Properties pane.

The Properties pane displays the metadata for the selected run or signal. You can edit properties using the white box in the Values column. When you view a comparison, the Simulation Data Inspector highlights metadata differences in red.

Columns in the navigation pane allow you to display signal properties in the table of signals under each run. To add or remove columns in the table, select the columns you want to display from the list on the Columns tab of the navigation pane's Preferences menu. Columns appear in the table in the order in which you select them.

Property NameValue
LineSignal line style and color
UnitsSignal measurement units
Data TypeSignal data type
ComplexitySignal type — real or complex
Complex FormatFormat for visualizing complex data
Sample TimeType of sampling
ModelName of the model that generated the signal
Block NameName of the signal's source block
Block PathPath to the signal's source block
PortIndex of the signal on the block's output port
DimensionsDimensions of the matrix containing the signal
ChannelIndex of signal within matrix
RunName of the simulation run containing the signal
Absolute ToleranceUser-specified, positive-valued absolute tolerance for the signal
Relative ToleranceUser-specified, positive-valued relative tolerance for the signal
Override Global ToleranceUser-specified property that determines whether signal tolerances take priority over global tolerances
Time ToleranceUser-specified, positive-valued time tolerance for the signal
Interp MethodUser-specified interpolation method used to plot the signal
Sync MethodUser-specified synchronization method used to coordinate signals for comparison
Time Series RootName of the variable associated with signals imported from the MATLAB workspace
Time SourceName of the array containing the time data for signals imported from the MATLAB workspace
Data SourceName of the array containing the data for signals imported from the MATLAB workspace

On the Compare pane, many parameters have a Baseline column and a Compare To column that you can display independently. If the Baseline and Compare to signals both have a property, but you can only display one property column, the column shows the Baseline property. In addition to the parameters listed for the Inspect pane, the Compare pane has columns specific to comparisons.

  • Max Difference — The maximum difference between the Baseline and Compare to signals

  • Align By — Primary signal alignment criterion specified in the Alignment tab of the Simulation Data Inspector Preferences menu

By default, the table displays the baseline name column and a column indicating whether the comparisons passed or failed.

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