imit_model / AnyLogic / UsersManual(AnyLogic)

AnyLogic V User’s Manual

ActiveObject

Figure 17. Inheritance among active object classes

Chapter 2. Replicated objects

2. Replicated objects

AnyLogic supports object replication - very easy and convenient way of modeling regularly organized structures of objects of arbitrary size and topology, such as vector, mesh, torus, hypercube, chain, ring, etc. AnyLogic saves you from the boring process of manual creation of the specified number of objects and establishing connections between them as this approach is limited, tedious, and forms the system with a predefined and constant number of objects.

In AnyLogic you simply declare a replicated object and specify the number of instances as a parameter. A replicated object represents a collection of active objects of the same class. Object replication provides very economical representation of complex structures of objects with arbitrary interconnections.

Object replication enables you to:

•Build scalable systems by creating replicated objects with the number of elements defined by a parameter of the model.

•Create complex structures of objects with sophisticated topologies by establishing arbitrary interconnections between replicated objects either from AnyLogic UI or programmatically.

•Model systems with dynamically changing structures by adding and removing objects to the group of replicated objects at runtime.

Do not confuse object replication with model replications. Model replication is a single model run and has nothing to do with object replication.

2.1 Creating a replicated object

In AnyLogic you can create a collection of objects of the same type simply by creating a replicated object. First, encapsulate an object you want to create a structure from, and then declare it replicated.

AnyLogic V User’s Manual

►To declare a replicated object

1.On the structure diagram, click the encapsulated object you want to make replicated.

2.On the Replication page of the Properties window, specify the number of individual elements of the replicated object (the replication factor) in the Number of objects edit box.

The name of the replicated object is displayed on the structure diagram with the trailing asterisk.

2.1.1Replication factor parameterization

You can specify any expression evaluating to integer or double type as a number of elements of the encapsulated object. Thus, you can parameterize the number of object instances in a replicated object. You may need this to facilitate modifying the number of objects of several replicated objects. See Chapter 3, “Parameters” for more information on parameters.

If you use a parameter as a replication factor of an encapsulated object, AnyLogic creates a number of instances equal to the initial value of the parameter. However, AnyLogic does not automatically adjust the number of instances in case you change the parameter at runtime. If such behavior is needed, you should use the handler method onChange_myParam() to take care of creation and destruction of instances (see Chapter 15, “Creating a model with dynamically changing structure”).

2.2Accessing and modifying a replicated object at runtime

This section describes accessing individual elements of a replicated object from code and creation/removing objects to/from a group of replicated objects at runtime. See section 15.1, “Manual creation and destruction of encapsulated objects” for general information about creating and destroying encapsulated objects at runtime.

AnyLogic V User’s Manual

2.3 Connecting replicated objects

AnyLogic provides a convenient mechanism of creating structures of objects with sophisticated topologies. It supports arbitrary types of interconnections between individual elements of replicated objects and between a replicated object and other objects (probably, also replicated).

First, this section describes how to connect ports and variables of replicated objects graphically. Then the information on establishing arbitrary types of interconnections between replicated objects is given. As connection rules are the same for variables and ports, they are described generally for interface elements of replicated objects.

2.3.1 Connecting interface elements of replicated objects graphically

►To connect interface elements of replicated objects

1.Drag the interface element of one object onto the interface element of another object, or

Click the Connector toolbar button, click the first interface element and then click the second interface element, or

Choose Draw|Structure|Connector from the main menu, click the first interface element and then click the second interface element.

The connector linking two interface elements appears (see Figure 18).

Figure 18. Interface elements of replicated objects connected

When you connect two replicated objects using a connector, you get configurations shown in Figure 19, i.e. each element in the client vector is connected with the server object.

AnyLogic V User’s Manual

2.In the Properties window, specify individual elements of the replicated object to be connected to the interface element of the other object from the Connect from ‘interface element’ of drop-down list:

All objects – the default value. Interface elements of all individual elements of the objects replicated object are connected to the interface element of the other object.

First of objects – the interface element of the first individual element only is connected. Last of objects – the interface element of the last individual element only is connected.

Figure 20 illustrates all these connection types.

Figure 20.

You may connect interface elements of two replicated objects as well. By default, interface elements of all object copies of one replicated object are connected to interface elements of all object copies of another replicated object (see Figure 19).

However, you can connect interface elements of certain object copies only. Therefore you need to specify the object copies of replicated objects you want to connect. This is done in

AnyLogic V User’s Manual

2.3.3Connecting individual elements of a replicated object

You may specify arbitrary interconnections between individual object copies of a replicated object. You can connect the same or different interface elements of some individual elements of a replicated object. Connect them in the same manner as you connect individual elements of a replicated object with another object.

►To connect individual elements of a replicated object

1.In the structure diagram, connect the required interface elements of the replicated object. You can connect an interface element to itself.

2.Select the created connector in the structure diagram.

3.In the Properties window, specify individual elements of the replicated object you want to connect for each connected interface element in Connect from ‘interface element’ of and To ‘interface element’ of drop-down lists.

Choose All objects, First of objects, or Last of objects to connect all individual elements, the first individual element, or the last individual element of the objects replicated object only.

You can connect interface elements of the same object copies in a vector of replicated objects by choosing objects(i) from both drop-down lists.

Also, you can connect interface elements of the adjacent object copies by choosing objects(i) and objects(i+1).

Some connection cases are shown in Figure 22.

Chapter 2. Replicated objects

Figure 22. Regular interconnections in a vector of replicated objects

Thus, in AnyLogic you can easily create a regularly structured system.

2.3.4Connecting replicated objects programmatically

Sometimes you may need to create a complex structure of objects with sophisticated topologies that cannot be established graphically. Or you may need to model a system with dynamically changing connections. Use the methods connect() and disconnect() to establish connections between replicated objects and their individual elements at runtime.

Use the connect()/disconnect() methods of the Port or VariableRef classes to connect/disconnect ports or variables of two objects. The methods take two arguments: two port objects, or two variable objects. The name of a port object is the name of the port in