Compare and Merge Simulink Models

This example shows how to view and merge the changes between two Simulink® models from the comparison report.

This example shows you how to use the comparison report in MATLAB to understand what has changed between two different designs. An engineer has made some changes to the model slxml_aircraft1 and the resulting model is slxml_aircraft2. The Simulink Model Comparison report will show you what these changes are and enable you to create another model containing changes from each of the two source models.

Compare The Models

Setup the example files by running the following command.

% Then use visdiff to compare the models.
visdiff('slxml_aircraft1', 'slxml_aircraft2');

Understand The Results

The Comparison Tool shows a report that only includes the differences between the two models, not the complete model hierarchies.

Colors indicate if items have been modified (purple items), inserted (blue items), or deleted (yellow items).

Stepping Through Differences

Use the "Next" and "Previous" navigation buttons on the Comparison tab to step through groups of changes in the report. When you do this to select an item:

  • The report highlights the corresponding item in the other tree (if it exists)

  • Both models display next to the report. The report highlights the corresponding item in the Simulink model, if possible.

You can control highlighting in the highlight toolstrip section.

Filtering Results

You can control the type of changes displayed in the comparison report by applying filters. To see the available filters, and whether or not they are applied to the current report, on the Comparison tab, in the Filter section, click the down arrow to expand the filter gallery. Click filter names to toggle whether they are applied. In the Filter section, click Show or Hide to control how the filters are applied.

For example, some information in the Simulink model file is defined as being "nonfunctional". These are changes that are unlikely to change the behavior of the design. Nonfunctional items are hidden by default but you can show them by deselecting the 'Nonfunctional Changes' item in the list of 'Built-In Filters' when the 'Hide' filter toolstrip button is selected.

Publish Results

It is possible to create a document containing a record of the changes made to a Simulink model using the "Publish" toolstrip option. Select the 'HTML' publish menu item to create an HTML report. Microsoft Word® reports can also be created by using the 'Word' menu item.

Merge Changes in Simulink Models

You can merge the changes between the two Simulink models by clicking the 'Merge Mode' button in the toolstrip. This creates a third file, 'targetFile', which can contain the changes from either the left model (slxml_aircraft1) or right model (slxml_aircraft2). To select which changes you would like in the target file use the radio buttons in the right of the report.

Once you have selected the changes you want in the target model you can save these changes over the right model (slxml_aircraft2) using the 'Save File' toolstrip button.

Note that in order for the tool to automatically connect merged lines, you must merge blocks before lines.

Further Information

Compare Simulink Models