systemcomposer.loadActivity

Load activity diagram model

Since R2026a

Syntax

activity = systemcomposer.loadActivity(activityName)

Description

activity = systemcomposer.loadActivity(activityName) loads the activity model specified by activityName and returns the systemcomposer.activity.Model object. The loaded model is not displayed. The activity model must exist on the MATLAB^® path.

Examples

Load Activity

Create, save, and load an activity model. Display the model properties.

adModel = systemcomposer.createActivity('authorActivity');
save(adModel);
close(adModel);
loadedActivity = systemcomposer.loadActivity('authorActivity')

loadedActivity = 

  Model with properties:

               Name: 'authorActivity'
     SimulinkHandle: 159.0007
    TypesDictionary: [1×1 systemcomposer.interface.Dictionary]
           Profiles: [0×0 systemcomposer.profile.Profile]
           Activity: [1×1 systemcomposer.activity.Activity]

Input Arguments

activityName — Name of activity model

character vector | string

Name of the activity model, specified as a character vector or string.

Example: 'authorActivity'

Data Types: char | string

Output Arguments

activity — Activity model

activity model object

Activity model, returned as a systemcomposer.activity.Model object.

More About

Definitions

Term	Definition	Application	More Information
Activity	An activity describes system behavior that models the flow of tokens from inputs to outputs through a controlled sequence of actions. An activity diagram contains action nodes with pins connected by flow lines.	Use activity to conceptualize a system, visualize functional flow through actions or decisions, and understand how system components interact with one another.	Describe System Behavior Using Activity Diagrams Create New Activity Diagram
Token	Tokens are objects that flow in the activity diagram. A token can represent data such as structures and integers, or a token can simply pass on the control.	An object token represents an object, such as a piece of data. A control token represents a control or a triggering event that does not carry any data.	Use Control Nodes to Manipulate Token Flows Use MATLAB Action Node Without MATLAB Function to Initialize Object Token
Action node	An action node is a key building block in an activity diagram. An action node represents an action to be executed. Action nodes consume input tokens and produce output tokens on pins.	Use a MATLAB function or a nested activity diagram to describe the behavior of an action node.	Author Action Node with MATLAB Function Behavior Use Nested Activity to Describe Action
Control node	A control node routes a logical flow of tokens through the system.	Use control nodes and flows to route tokens. Control nodes can be used to initialize, split, merge, and terminate token flows.	Use Control Nodes to Manipulate Token Flows
Pin	A pin acts as a buffer for object tokens and directs tokens into or out of an action node. The directionality of the pin represents input or output. You can connect pins by object flows.	Use pins to route an object token to or from an Action Node. Pins are also used to store object tokens before or during execution. You can use pins only for object flows.	Author a Simple Activity Diagram Types Editor
Type	A type defines the contents of a token that flows through a pin. A type has dimension, unit, complexity, minimum, maximum and description.	A value type token is a type assigned to a single value. A composite type token is equivalent to a bus structure that contains field of different values and data types. A MATLAB class type token references a MATLAB class on the path that defines a complex object with properties and methods. You can use a built-in MATLAB class or define your own MATLAB class.	Action Node Types Editor Model Complex Objects in Activity Diagrams Using MATLAB Class Tokens
Parameter node	A parameter node routes tokens into or out of a nested activity diagram. When a pin is created, a corresponding parameter node will be created inside the nested activity.	Use a parameter node to define how tokens enter or leave a nested activity. There are two types of parameter nodes input and output.	Use Nested Activity to Describe Action
Flow	A flow in an activity diagram connects two nodes. A dashed line represents a control flow. A solid line represents an object flow.	Tokens in an object flow contains token data on which actions operate. You can use object flows to route input or output tokens to carry information or physical items between object nodes. Tokens in a control flow trigger the execution of actions. You can use control flows to model transfer of control from one Action Node to another.	Simulate, Visualize, and Validate Activity Diagrams

Version History

Introduced in R2026a