{"data":{"markdownRemark":{"html":"

Annotations are used to mark fields in the model. This is important to identify the model as a specific type so that the Simudyne SDK has knowledge of these fields when running the model.

\n

@ModelSettings

\n

ModelSettings is an optional annotation that allows you to set a number of configuration parameters, such as the default time settings.

\n

Optional ModelSettings parameters:

\n\n
public class MyModel extends AgentBasedModel<GlobalState> {\n@ModelSettings(kickoff = 10, end = 100, timeUnit = \"MONTHS\")\npublic class CreditCard implements Model {\n  ...\n}
\n

@Constant

\n

Fields can be marked as Constant to highlight that this field is available for configuration before setup() has been called on the model. Constant is useful for configurable parameters that will be used during the model setup such as the number of agents.

\n

name can be passed as an optional parameter to the constant annotation to set a human-friendly name for the input field in the console. If not set, the name of the field will be used.

\n

Constant.Java

\n
public class CreditCard implements Model {\n  @Constant(name = \"Initial Balance\")\n  public long initialBalance = 400;\n\n  public void setup() {\n    // set balance to value of initialBalance\n  }\n}
\n

Console view of constant before setup (value can be changed).

\n
\n![](/src/images/constant_2_1.png)\n
\n
\n Constant fields must be public, with a primitive type (int, float, boolean etc).\n
\n

@Input

\n

Fields can be marked as Input to show that this field is available for configuration in the model at all times. Input fields are used to highlight where particular parameters in the model may be involved in ongoing decisions.

\n

As with @Constant, name can be used as an optional parameter to set a human-friendly title for the input field in the console. If this is not set, the name of the field will be used.

\n

Input.Java

\n
public class CreditCard implements Model {\n  @Input(name = \"Spending\")\n  public float spending = 250f;\n\n  public void step() {\n    // use value of spending\n  }\n}
\n
\n Input fields must be public, with a primitive type (int, float, boolean etc).\n
\n

@Variable

\n

Fields marked as Variable are serialised as part of the model output after setup has been run.\n(This means that it is safe to depend upon state that is initialised as part of setup from a @Variable method (such as an AgentSystem)).

\n

For more information on Variable see Outputting Data

\n
\n Variable fields must be public, with a supported type (Read more about supported types).\n
\n

@Output

\n

Currently Outputs and Variables are considered the same thing, and can be used in the same way.

\n
\n Ouput fields must be public, with a supported type (Read more about supported types).\n
\n

@Custom

\n

Fields marked as custom are objects which have fields of their own with annotations.

","headings":[{"value":"@ModelSettings","depth":2},{"value":"@Constant","depth":2},{"value":"@Input","depth":2},{"value":"@Variable","depth":2},{"value":"@Output","depth":2},{"value":"@Custom","depth":2}],"frontmatter":{"title":"Annotations","toc":null,"experimental":null}},"site":{"siteMetadata":{"title":"Simudyne Docs","latestVersion":"2.6"}}},"pageContext":{"absolutePath":"/home/vsts/work/1/s/content/2.5/reference/modelling/annotations.md","versioned":true,"version":"2.5","kind":"reference","pagePath":"/reference/modelling/annotations","chronology":{"prev":{"name":"Model Initialisation","path":"/reference/modelling/model-initialisation"},"next":{"name":"Model Context","path":"/reference/modelling/model-context"}},"lastUpdated":"2026-04-21T13:56:54.862Z"}}