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Create alias for signal and/or parameter data type
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 software 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 software 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.
Note Suppose you specify an instance of the Simulink.AliasType class as the value of a Simulink.Parameter object's Data type property. If you enter the parameter object in a subsystem's mask, the subsystem displays the data type's base type instead of its alias name. |
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 Base Workspace (i.e., 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 software displays an error.
Select Simulink.AliasType from the Model Explorer's Add menu.
Simulink software 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).
Use the MATLAB save command to save the newly created alias in a MAT-file that can be loaded by the models in which it is used.
Use the following syntax to create a data type alias at the MATLAB command line or in a MATLAB program
ALIAS = Simulink.AliasType;
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.AliasType;
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.
old = MyFloat.BaseType; MyFloat.BaseType = 'single';
See Properties for information on the names, permitted values, and usage of the properties of data type alias objects.
You can cause data type aliases to appear in the code generated for a model using any of the following methods.
Specifying the signal data type of a block in the model as a Simulink.AliasType via the Block Parameters dialog box.
Creating a Simulink.Signal object that uses the Simulink.AliasType as its data type. Use this signal object as the name of a signal in the model and specify that the signal name must resolve to an object in the MATLAB workspace. See Signal Objects in the Real-Time Workshop® User's Guide for more information.
Creating a Simulink.Parameter object that uses the Simulink.AliasType as its data type. Use this parameter object as a block parameter in the model. SeeGenerated Code for Parameter Data Types in the Real-Time Workshop User's Guide for more information.
None
None.
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.
Note Fixed-point: unspecified scaling is a partially specified type whose definition is completed by the block that uses the Simulink.NumericType. Forbidding its use in alias types avoids creating aliases that have different base types depending on where they are used. |
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.
Describes the usage of the data type referenced by this alias.
Name | Description |
|---|---|
A string specifying the name of a standard or custom data type. (Base Type) | |
A string that describes the usage of the data type. May be a null string. (Description) | |
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.Annotation | |
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