Model Workspaces - MATLAB & Simulink (original) (raw)

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Model Workspace Differences from MATLAB Workspace

Each model is provided with its own workspace for storing variable values.

The model workspace is similar to the base MATLAB® workspace except that:

• Variables in a model workspace are visible only in the scope of the model.
  If both the MATLAB workspace and a model workspace define a variable of the same name, and the variable does not appear in any intervening masked subsystem or model workspaces, the Simulink® software uses the value of the variable in the model workspace. A model's workspace effectively provides it with its own name space, allowing you to create variables for the model without risk of conflict with other models.
• When the model is loaded, the workspace is initialized from a data source.
  The data source can be a Model file, a MAT file, a MATLAB file, or MATLAB code stored in the model file. For more information, see Data Source.
• You can interactively reload and save MAT file, MATLAB file, and MATLAB code data sources.
• To store a signal object in a model workspace, set the storage class of the object to Auto. Signal objects includeSimulink.Signal and subclasses that you create.
  If you specify a storage class other than Auto, you must store signal objects in the base workspace or a data dictionary to ensure the objects are unique within the global Simulink context and accessible to all models.
• When you store MATLAB variables and parameter objects (such asSimulink.Parameter) in a model workspace, some tunability limitations apply. See Tunability Considerations and Limitations for Other Modeling Goals. In addition, if you store anAUTOSAR.Parameter object in a model workspace, the code generator ignores the storage class that you specify for the object.
  When you store Simulink.NumericType objects you cannot use the object as a data type alias. You must set theIsAlias property tofalse.

Note

When resolving references to variables used in a referenced model, the variables of the referenced model are resolved as if the parent model did not exist. For example, suppose a referenced model references a variable that is defined in both the parent model's workspace and in the MATLAB workspace but not in the referenced model's workspace. In this case, the MATLAB workspace is used.

Troubleshooting Memory Issues

When you use a workspace variable as a block parameter, Simulink creates a copy of the variable during the compilation phase of the simulation and stores the variable in memory. This can cause your system to run out of memory during simulation, or in the process of generating code. Your system might run out of memory if you have:

• Large models with many parameters
• Models with parameters that have a large number of elements

This issue does not affect the amount of memory that is used to represent parameters in generated code.

Manipulate Model Workspace Programmatically

For most common data management tasks, regardless of data source, you can use theSimulink.data.connect function to create a connection to your data source, then use the common set of functions provided by the Simulink.data.DataConnection object. For more information, see Manage Design Data for Simulink Models Programmatically.

For tasks specific to a model workspace, use a Simulink.ModelWorkspace object. An object of the Simulink.ModelWorkspace class describes a model workspace. Simulink creates an instance of this class for each model that you open during a Simulink session. The methods associated with this class can be used to accomplish a variety of tasks related to the model workspace, including:

• Listing the variables in the model workspace
• Assigning values to variables
• Evaluating expressions
• Clearing the model workspace
• Reloading the model workspace from the data source
• Saving the model workspace to a specified MAT-file or MATLAB file
• Saving the workspace to the MAT-file or MATLAB file that the workspace designates as its data source

See Also

Simulink.ModelWorkspace | Simulink.data.DataConnection | Simulink.data.connect

Topics

• Specify Source for Data in Model Workspace
• Change Model Workspace Data
• Determine Where to Store Variables and Objects for Simulink Models
• Configure Instance-Specific Values for Block Parameters in a Referenced Model
• Manage Design Data for Simulink Models Programmatically