An S4 Class to Represent Goals

Defines the goal class, which contains all characteristics of a goal that the agents can pursue.

Slots

id: Character that serves as an identifier for the goal.
position: Numerical vector denoting the position of the goal.
path: Numerical matrix of size n x 2 denoting the different intermediate path points between an agent and a goal. In effect defines which path the agent will take to move towards the goal.
busy: Logical denoting whether the goal is currently being interacted with.
done: Logical denoting whether a goal has been completed.
counter: Numeric denoting the number of time steps the agent should interact with the goal before the goal has been completed.