Quick Programming References

Designer Architecture

Numerus Designer is a platform for building and running simulations. A simulation requires a set of state values and a clock that iterates through a sequence of time units. The simulation uses the current state at a given point in time to determine the next state. In Designer, the state is factored across a set of interacting Components managed by a container called a Capsule.

Capsules

• The fundamental structural unit for Designer is the Capsule.
• A Capsule is comprised of a set of interacting elements called Components.
• Each Capsule actually acts as a class, or blueprint for creating one or more instances of its Component set. This is true except for the top-level Capsule, for which there is only a single instance.
• When starting a new project, you are provided with an empty canvas on which to design the top-level Capsule. Many models only require a top-level Capsule. Additional Capsules are used to implement Cells and Agents in cellular and/or agent-based models. Capsules are also used to define new Components for use in other Capsules.

Components

• Components compute useful functions or serve as containers for Agents or Cells.
• Components are either stateful or stateless. Stateful Components manage some part of the state. State values determined by these components are carried from the current time step to the next. Stateless Components compute values from the current state of the simulation that are used to determine the next values for stateful Components, but these values are not retained across the transition from one time unit to the next.
• Most Components need to be programmed; i.e., provided with values or code that determine their behavior. Within that code may be references to the current values of other Components. The simplest Component programming calls for one or more constant values, however for most Components a code segment using the Java language is required.
• User-defined code segments are called squibs. Each squib either computes and returns a value, or performs a state change. The bulk of Designer programming is in writing squibs.