Built-in Properties

List of Built-in Properties

Built-in Property	Data Type	Belong to	Agent	Cell	Link	Assigned during initialization	Modified by formulas	Modified by components	Dependencies
Tick	Number	Global
Now	DateTime	Global
ID	Number	Individual							Entity
Color	String	Individual							Cell/Link
Size	Number	Individual							Cell/Link
Shape	String	Individual							Cell/Link
Coordinates	List[Number]	Individual						Move/Place At	Cell
Coordinates	List[Number]	Individual							Cell
Angle	Number	Individual						Move	Cell
CurrentSpace	Cell Observer	Individual						Place At	Cell
CurrentCell	Cell	Individual							Cell
LineType	String	Individual							Link
Thickness	Number	Individual							Link
Ends	List[Agent]	Individual							Link
Weight	Number	Individual							Link
PopulationSize	Number	Observer							Entity
Individuals	List[Entity]	Observer							Entity
Nodes	List[Agent]	Observer							Link
MaxX	Number	Observer							Cell
MinX	Number	Observer							Cell
MaxY	Number	Observer							Cell
MinY	Number	Observer							Cell

Notes

• Built-in properties of entities can be overridden by custom properties with the same name.
• For the data type of entity, any instance not explicitly identified as an Observer refers to individual objects.
• The Now property only holds a value when the simulation is set to calendar mode in the global model settings.
• The table's rightmost "Dependencies" column shows how the system dynamically creates built-in properties based on entity types in your model. While this doesn't affect modeling features (like formula bar smart suggestions, quotes, ask-to-access, etc.), you must include the required entity types that built-in properties depend on in your model to avoid runtime errors.

Description of Built-in Property Functions

Built-in Property	Global	Agent	Cell	Link
Tick	Current simulation step
Now	Calendar time of the current simulation step
ID		Unique natural number identifier of the individual	Unique natural number identifier of the individual	Unique natural number identifier of the individual
Color		Color: The color of an entity, configurable to display specific visual effects within the WorldView and Network View Charts. For detailed values, refer to the Usage of Color Properties.	Color of the entity; it can be displayed in charts	Color of the entity; it can be displayed in charts.
Size		Size of the Agent; it can be represented in relevant charts.
Shape		The shape of an Agent, which configurable to display specific visual effects within the Worldview Charts. The system supports various enumerated values, as detailed in the notes below.
Coordinates		Coordinates of the Agent in space	Nominal position of the Cell, i.e., its center coordinates
Angle		Orientation angle of the Agent, [0,360). 0° is East, 90° is North.
CurrentSpace		The space where the Agent is currently located
CurrentCell		The grid cell where the Agent is currently located
LineType				Line type of the Link entity. It can be set to show specific visual effects within the network view, using various enumerated values as detailed below.
Thickness				Line width of the Link entity. It can be adjusted to display specific visual effects within the network view.
Ends				The Agents at both ends of the Link entity
Weight				Strength of the Link entity. When using methods to obtain closely related entities, distance can be calculated based on weight. Non-negative value.
PopulationSize		Population size	Population size	Population size
Individuals		All individuals in the population	All individuals in the population	All individuals in the population
Nodes				All Agents in the network graph
MaxX			Maximum X coordinate of a Cell in the space.
MinX			Minimum X coordinate of a Cell in the space.
MaxY			Maximum Y coordinate of a Cell in the space.
MinY			Minimum Y coordinate of a Cell in the space.

Notes

1. Shape Values and Corresponding Icons: Refer to the table below for details, with the default being arrow.

Shape	Icon
arrow
ant
sheep
person
car
circle
wolf

2. LineType: The system supports the following enumerated values: solid, dashed, and dotted, with the default being solid.

Using Color Properties

• The Color built-in property is formatted as a string value. For example, it can be set to blue or a hexadecimal color code like #0000FF.
• HoloBit supports CSS Color standard RGB notation. You can use string names and hexadecimal color codes directly. See https://www.w3.org/TR/css-color-4/#named-colors for details.
• You can also use the global function rgb(Number1, Number2, Number3) provided by the system to return the color you need.

Model Example

Gradient Function

Usage of Built-in Properties in Modeling

• The usage of built-in properties is the same as regular custom properties.
• You can drag and drop quotes for these properties onto the canvas for graphical modeling.
• Within the scope, you can directly use the built-in properties' names in formulas or expressions. Outside the scope, you can access built-in properties using the format entity_object.property_name.