Coupled

Coupled models describes a system as a network of components coupled together. These components are in the modular form, which means their interactions are restricted to happen through identified ports with a preestablished connection.

Coupled models are themselves modular models, which means they also have input and output ports. Thus, it is possible to build a hierarchy of models shaped as a tree, which helps modellers managing complexity.

Coupled models are defined under the Quartz::CoupledModel class. They can either be instantiated directly or inherited. In both cases, the API to add sub-models and coupling them is identical.

We will re-use our running example from the atomic model page to connect models.

Adding sub-models

Adding sub-models is done using the #add_child method or the #<< alias method.

In the example below we build a model of a store, with 2 cashiers and 2 client queues:

class SmallStoreModel < Quartz::CoupledModel
  def after_initialize
    cashier1 = Cashier.new("cashier1")
    cashier2 = Cashier.new("cashier2")
    queue1 = Clients.new("queue1")
    queue2 = Clients.new("queue2")
    counter = Counter.new("counter")

    self << cashier1 << cashier2 << queue1 << queue2 << counter
  end
end

Internal couplings

Now we need to couple output ports with input ports between sub-models, using the #attach method, which expects an output port and a target input port:

attach(sender.output_port("out"), receiver.input_port("in"))

or using port names instead of a reference to the ports:

attach "output_port_name", to: "input_port_name", between: sender, and: receiver
# or also
attach "output_port_name", to: "input_port_name", between: "sender_name", and: "receiver_name"

Transducers

External input couplings

External output couplings