MATLAB Function Block Editor

Customizing the MATLAB Function Block Editor

Use the toolbar icons to customize the appearance of the MATLAB Function Block Editor in the same manner as the MATLAB editor. See Adjust Desktop Appearance in the MATLAB documentation.

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MATLAB Function Block Editor Tools

Use the following tools to work with the MATLAB Function block:

See Defining Inputs and Outputs for an example of defining an input argument for a MATLAB Function block.

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Editing and Debugging MATLAB Function Block Code

Commenting Out a Block of Code

To comment out a block of code in the MATLAB Function Block Editor:

1. Highlight the text that you would like to comment out.

2. Hold the mouse over the highlighted text and then right-click and select Comment from the context menu. (Alternatively, select Comment from the Text menu).

Note   To uncomment a block of code, follow the same steps, but select Uncomment instead of Comment.

For more information, refer to Add Comments in the MATLAB Desktop Tools and Development Environment documentation.

Manual Indenting

To indent a block of code manually:

1. Highlight the text that you would like to indent.

2. Select one of the following options:

   • Smart Indent from the Text menu.

   • Decrease Indent from the Text menu.

   • Increase Indent from the Text menu.

For more information, refer to Indent Code in the MATLAB Desktop Tools and Development Environment documentation.

Opening a Selection

You can open a subfunction, function, file, or variable from within a file in the MATLAB Function Block Editor.

To open a selection:

1. Position the cursor in the name of the item you would like to open.

2. Right-click and select Open <selection> from the context menu.

The Editor chooses the appropriate tool to open the selection. For more information, refer to Evaluate or Open Code You Select in the MATLAB Desktop Tools and Development Environment documentation.

Note   If you open a MATLAB Function block input or output parameter, the Ports and Data Manager opens with the selected parameter highlighted. You can use the Ports and Data Manager to modify parameter attributes. For more information, refer to Ports and Data Manager.

Evaluating a Selection

You can use the Evaluate a Selection menu option to report the value for a MATLAB function variable or equation in the MATLAB window during simulation.

To evaluate a selection:

1. Highlight the variable or equation that you would like to evaluate.

2. Hold the mouse over the highlighted text and then right-click and select Evaluate Selection from the context menu. (Alternatively, select Evaluate Selection from the Text menu).

When you reach a breakpoint, the MATLAB command Window displays the value of the variable or equation at the Command Line Debugger prompt.

debug>> stdev
 
	1.1180

debug>> 

Note   You cannot evaluate a selection while MATLAB is busy, for example, running a MATLAB file.

Setting Data Scope

To set the data scope of a MATLAB Function block input parameter:

1. Highlight the input parameter that you would like to modify.

2. Hold the mouse over the highlighted text and then right-click and select Data Scope for <selection> from the context menu.

3. Select:

   • Input if your input data is provided by the Simulink model via an input port to the MATLAB Function block.

   • Parameter if your input is a variable of the same name in the MATLAB or model workspace or in the workspace of a masked subsystem containing this block.

For more information, refer to Setting General Properties in the Ports and Data Manager documentation.

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Ports and Data Manager

The Ports and Data Manager provides a convenient method for defining objects and modifying their properties in a MATLAB Function block that is open and has focus.

The Ports and Data Manager provides the same data definition capabilities as the Model Explorer, but supports only individual MATLAB Function blocks. To learn how to modify objects and properties for blocks across the model hierarchy, see The Model Explorer: Overview.

Ports and Data Manager Dialog

The Ports and Data Manager dialog box allows you to add and define data arguments, input triggers, and function call outputs for MATLAB Function blocks. Using this dialog, you can also modify properties for the MATLAB Function block and the objects it contains.

The dialog consists of two panes:

• The Contents pane lists the objects that have been defined for the MATLAB Function block.

• The Dialog pane displays fields for modifying the properties of the selected object.

Properties vary according to the scope and type of the object. Therefore, the Ports and Data Manager properties dialogs are dynamic, displaying only the property fields that are relevant for the object you add or modify.

When you first open the dialog box, it displays the properties of the MATLAB Function block.

Opening the Ports and Data Manager

To open the Ports and Data Manager from the MATLAB Function Block Editor, select Tools > Edit Data/Ports. The Ports and Data Manager appears for the MATLAB Function block that is open and has focus.

Ports and Data Manager Tools

The following tools are specific to the Ports and Data Manager:

MATLAB Function Block Properties

This section describes each property of a MATLAB Function block.

Name.  Name of the MATLAB Function block, following the same naming conventions as for Simulink blocks (see Manipulating Block Names).

Update method.  Method for activating the MATLAB Function block. You can choose from the following update methods:

Saturate on integer overflow.  Option that determines how the MATLAB Function block handles overflow conditions during integer operations:

Note   The Saturate on integer overflow option is relevant only for integer arithmetic. It has no effect on fixed-point or double-precision arithmetic.

When you enable Saturate on integer overflow, MATLAB adds additional checks during code generation to detect integer overflow or underflow. Therefore, it is more efficient to disable this option if you are sure that integer overflow and underflow will not occur in your MATLAB Function block code.

Even when you disable this option, the code for a simulation target checks for integer overflow and underflow. If either condition occurs, simulation stops and an error is generated. If you enable debugging for the MATLAB Function block, the debugger displays the error and lets you examine the data.

If you did not enable debugging, the block generates a run-time error:

Overflow detected. Enable debugging for more information.

Note that the code generated by Simulink Coder does not check for integer overflow or underflow and, therefore, may produce unpredictable results when Saturate on integer overflow is disabled. In this situation, it is recommended that you simulate first to test for overflow and underflow before generating code.

Lock Editor.  Option for locking the MATLAB Function Block Editor. When enabled, this option prevents users from making changes to the MATLAB Function block.

Treat these inherited Simulink signal types as fi objects.  Parameter that applies to MATLAB Function blocks in models that use fixed-point or integer data types. You can control how the MATLAB Function block handles Simulink input signals using the Treat these inherited Simulink signal types as fi objects parameter.

MATLAB Function block fimath.   Setting that defines fimath properties for the MATLAB Function block. The block associates the fimath properties you specify with the following objects:

• All fixed-point and integer input signals to the MATLAB Function block that you choose to treat as fi objects.

• All fi and fimath objects constructed in the MATLAB Function block.

You can select one of the following options for the MATLAB Function block fimath.

Description.  Description of the MATLAB Function block.

Document link.  Link to documentation for the MATLAB Function block. To document a MATLAB Function block, set the Document link property to a Web URL address or MATLAB expression that displays documentation in a suitable format (for example, an HTML file or text in the MATLAB Command Window). The MATLAB Function block evaluates the expression when you click the blue Document link text.

Adding Data to a MATLAB Function Block

You can define data arguments for MATLAB Function blocks using the following methods:

Defining Data in the Ports and Data Manager.  To add a data argument and modify its properties, follow these steps:

1. In the Ports and Data Manager, select Add > Data

   The Ports and Data Manager adds a default definition of the data to the MATLAB Function block.

   

2. Modify data properties.

3. Return to the MATLAB Function block properties at any time by selecting Tools > Block Dialog.

Defining Data in the Model Explorer.  The Data properties dialog in the Model Explorer allows you to set and modify the properties of data arguments in MATLAB Function blocks. Properties vary according to the scope and type of the data object. Therefore, the Data properties dialog is dynamic, displaying only the property fields that are relevant for the data argument you are defining.

Open the Data properties dialog by selecting a data argument in the Contents pane. The Data properties dialog provides a set of tabbed panes for defining different features of your data argument:

• The General tab lets you define the scope, size, complexity, type, and limit range of the data argument. See Setting General Properties.

• The Description tab lets you save values to the base workspace, enter a description, and link to documentation about the data argument. See Setting Description Properties.

Setting General Properties.  You can set the following properties in the General tab:

Setting Description Properties.  You can set the following properties on the Description tab:

Adding Input Triggers to a MATLAB Function Block

An input trigger is an event on the input port that causes the MATLAB Function block to execute. See Triggered Subsystems in the Simulink documentation.

You can define the following types of triggers in MATLAB Function blocks:

• Rising

• Falling

• Either (rising or falling)

• Function call

For a description of each trigger type, see Setting Input Trigger Properties.

Use the Ports and Data Manager to add input triggers to a MATLAB Function block that is open and has focus. To add an input trigger and modify its properties, follow these steps:

1. In the Ports and Data Manager, select Add > Input Trigger.

   The Ports and Data Manager adds a default definition of the new input trigger to the MATLAB Function block and displays the Trigger properties dialog.

   

2. Modify trigger properties.

3. Return to the MATLAB Function block properties at any time by selecting Tools > Block Dialog.

The Trigger Properties Dialog.  The Trigger properties dialog in the Ports and Data Manager allows you to set and modify the properties of input triggers in MATLAB Function blocks.

To open the Trigger properties dialog, select an input trigger in the Contents pane.

Setting Input Trigger Properties.  You can set the following properties in the Trigger properties dialog:

Adding Function Call Outputs to a MATLAB Function Block

A function call output is an event on the output port of a MATLAB Function block that causes a function-call subsystem in the Simulink model to execute. A function-call subsystem is a subsystem that another block can invoke directly during a simulation. See Function-Call Subsystems in the Simulink documentation.

Use the Ports and Data Manager to add and modify function call outputs to a MATLAB Function block that is open and has focus. To add a function call output and modify its properties, follow these steps:

1. In the Ports and Data Manager, select Add > Function Call Output.

   The Ports and Data Manager adds a default definition of the new function call output to the MATLAB Function block and displays the Function Call properties dialog.

   

2. Modify function call output properties.

3. Return to the MATLAB Function block properties at any time by selecting Tools > Block Dialog.

The Function Call Properties Dialog.  The Function Call properties dialog in the Ports and Data Manager allows you to edit the properties of function call outputs in MATLAB Function blocks.

To open the Function Call properties dialog, select a function call output in the Contents pane.

Setting Function Call Output Properties.  You can set the following properties in the Function Call properties dialog:

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Debugging a MATLAB Function Block

Working with MATLAB Function Reports

Related Products & Applications

• Simulink
• Control Design
• Signal Processing & Communications
• Model-Based Design
• Physical Modeling
• Verification & Validation

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