The global state is an object that can be read by all agents.
\nIf your model doesn't need to make use of a global state, Agents and the AgentBasedModel need to be typed as GlobalState in order for the model to compile.
Generifying agents with default GlobalState (java)
\npublic class MyModel extends AgentBasedModel<GlobalState> {}\n\npublic static final class MyAgent extends Agent<GlobalState> {}If you have some global state to be shared across the system, create a Globals class that extends GlobalState, and pass as a type to the AgentBasedModel. Agents will now need to be typed as Globals in order to access values inside Globals.
Creating a custom global object(java)
\npublic class MyModel extends AgentBasedModel<MyModel.Globals> {\n public static final class Globals extends GlobalState {\n public float preference = 0.35f;\n }\n}\npublic static final class MyAgent extends Agent<Globals> {}To get the globals values and update them from inside the model setup or step
Accessing a global from model (java)
\npublic class MyModel extends AgentBasedModel<MyModel.Globals> {\n public static final class Globals extends GlobalState {\n float fillFactor = 0.25f;\n }\n\n public void setup() {\n getGlobals().fillFactor = 0.5;\n super.setup();\n }\n}To get the globals values from inside the Agents
Accessing a global from and agent (java)
\npublic static final class MyAgent extends Agent<Globals> {\n private void updateHappiness() {\n long similar = // calculate similar\n long total = // calculate total\n\n float preference = getGlobals().preference;\n this.person.happy = (float) similar / total > preference;\n }\n }Annotations can be used inside the global state to set the values of the global state from the console, or to report a global state value.
\nAnnotating a global variable(java)
\npublic static final class Globals extends GlobalState {\n @Input public float preference = 0.35f;\n}