Simulink.AliasType (Simulink Reference)

Create an alias for a signal and/or parameter data type

Description

This class allows you to designate MATLAB variables as aliases for signal and parameter data types. You do this by creating instances of this class and assigning them to variables in the MATLAB or model workspaces (see Creating a Data Type Alias). The MATLAB variable to which a Simulink.AliasType object is assigned is called a data type alias. The data type to which an alias refers is called its base type. Simulink allows you to set the BaseType property of the object that the variable references, thereby designating the data type for which it is an alias.

Simulink lets you use aliases instead of actual type names in dialog boxes and set_param commands to specify the data types of Simulink block outputs and parameters. Using aliases to specify signal and parameter data types can greatly simplify global changes to the signal and parameter data types that a model specifies. In particular, changing the data type of all signals and parameters whose data type is specified by an alias requires only changing the base type of the alias. By contrast, changing the data types of signals and parameters whose data types are specified by an actual type name requires respecifying the data type of each signal and parameter individually, a tedious and time-consuming process.

Creating a Data Type Alias

You can use either the Model Explorer or MATLAB commands (see MATLAB Commands for Creating Data Type Aliases) to create a data type alias.

To use the Model Explorer to create an alias,

Select the MATLAB workspace in the Model Explorer's Model Hierarchy pane.

You must create data type aliases in the MATLAB workspace. If you attempt to create an alias in a model workspace, Simulink displays an error.

Select Simulink.AliasType from the Model Explorer's Add menu.

Simulink creates an instance of a Simulink.AliasType object and assigns it to a variable named Alias in the MATLAB workspace.

Rename the variable to a more appropriate name, for example, a name that reflects its intended usage.

To change the name, edit the name displayed in the Name field in the Model Explorer's Contents pane.

Enter the name of the data type that this alias represents in the Base type field in the Model Explorer's Dialog pane.

You can specify the name of any existing standard or user-defined data type in this field. Skip this step if the desired base type is double (the default).

Save the newly created alias in a MAT-file loaded by the models in which it is used.

MATLAB Commands for Creating Data Type Aliases

Use the following syntax to create a data type alias at the MATLAB command line or in a MATLAB program

```
ALIAS = Simulink.Alias;
```

where ALIAS is the name of the variable that you want to serve as the alias. For example, the following line creates an alias names MyFloat.

```
MyFloat = Simulink.Alias;
```

The following notations get and set the properties of a data type alias, respectively,

PROPVALUE = ALIAS.PROPNAME;
ALIAS.PROPNAME = PROPVALUE;

where ALIAS is the name of the alias, PROPNAME is the name of the alias object's properties, and PROPVALUE is the property's value. For example, the following code saves the current value of MyFloat's BaseType property and assigns it a new value.

save = MyFloat.BaseType;
MyFloat.BaseType = 'single';

See the "Properties" section below for information on the names, permitted values, and usage of the properties of data type alias objects.

Property Dialog Box

Base type: The data type to which this alias refers. The default is double. To specify another data type, select the data type from the adjacent pull-down list of standard data types or enter the data type's name in the edit field. Note that you can, with one exception, specify a nonstandard data type, e.g, a data type defined by a Simulink.NumericType object, by entering the data type's name in the edit field. The exception is a Simulink.NumericType whose Category is Fixed-point: unspecified scaling.
Header file: Name of a user-supplied C header file that defines a data type having the same name as this alias (i.e., as the MATLAB variable that references this alias object). If this field is not empty, code generated from this model defines the alias type by including the specified header file. If this field is empty, the generated code defines the alias type itself.
Description: Describes the usage of the data type referenced by this alias.

Properties

Name
Description

BaseType
A string specifying the name of a standard or custom data type. (Base type)

Description
A string that describes the usage of the data type. May be a null string. (Description)

HeaderFile
A string that specifies the name of a C header file that defines a data type having the same name as the alias. (Header file)

Name	Description
`BaseType`	A string specifying the name of a standard or custom data type. (Base type)
`Description`	A string that describes the usage of the data type. May be a null string. (Description)
`HeaderFile`	A string that specifies the name of a C header file that defines a data type having the same name as the alias. (Header file)

EventData Simulink.BlockCompDworkData