Base class

type TaskCallback = Callable[list[float], None]

The type of callbacks called when the task publishes data related to an event. The task must publish data of the same size, see navground.sim.Task.log_size.

class Task

This class describe the high-level task control that provides navigation goals.

Sub-classes are expected to override methods

• prepare(), which is called at the begin of the simulation to set it up.

• update(), which is called at every simulation step.

• close, which is called at the end of the simulation.

add_callback(callback: TaskCallback) → None

Adds a callback called to log task events.

Parameters:

value – The desired callback

close() → None

Clean-up the task.

Called after finishing a simulation.

done() → bool

Returns whether the task is done.

Returns:

True if the task has finished.

dump() → str

Dumps the object to a YAML-string.

Returns:

The YAML representation

Return type:

str

get(name: str) → PropertyField

Gets the value of the specified property.

Parameters:

name – The name of the property

Raise:

RuntimeError A runtime error if no property is found.

Returns:

The value of the property

get_log_size() → int

The size of the data passed to callbacks when events occur, see TaskCallback and add_callback().

Returns:

The size of the data vector.

get_property_type_name(name: str) → str

Gets the type of a property.

Parameters:

name – The name of the property

Returns:

The property type name or an empty string if the property is not defined.

has(name: str) → bool

Checks whether a property exists.

Parameters:

name – The name of the property

Returns:

True if the property exists

static has_type(name: str) → bool

Check whether a type name has been registered.

Parameters:

type – The associated type name.

Returns:

True if the type name has been registered.

static load(value: str) → object

Load a task from a YAML string.

Parameters:

value – the YAML string.

Returns:

The loaded task or None if loading fails.

Return type:

Task| None

log_event(log: Sequence[SupportsFloat]) → None

Log an event, forwarding data to registered callbacks

Parameters:

log – The logged data

static make_type(name: str) → object

Create an object of a sub-class selected by name.

Parameters:

type – The associated type name.

Returns:

An object of a registered sub-class or None in case the desired name is not found.

prepare(agent: Agent, world: World) → None

Setup the task.

Called before starting a simulation.

Parameters:

• agent – The agent owning the task

• world – The world the agent is part of

static register_schema() → Schema

Returns the json-schema that includes registered components.

Returns:

“anyOf” json-schema of all registered components.

Return type:

navground.core.schema.Schema

static schema(reference_register_schema: bool = True, type: str | None = None) → Schema

Returns the json-schema of a component

Returns an empty dictionary if a not registered type is requested.

Parameters:

• reference_register_schema – Whether to reference registered components schema in the base class schema.

• type (str) – An optional registered type. If not specified, it returns the schema of the base class.

Returns:

A json-schema of the registered class

Return type:

navground.core.schema.Schema

set(name: str, value: PropertyFieldLike) → None

Set the value of a named property. Fails silently if no property can be found or if the value has a non-compatible type.

Parameters:

• name – The name of the property

• value – The desired value for the property

update(agent: Agent, world: World, time: SupportsFloat) → None

Tick the task, possibly updating the navigation goal of the agent.

Parameters:

• agent – The agent ticking the task

• world – The world the agent is part of

• time – The simulation time

property log_size

Type:

int

The size of the data passed to callbacks when events occur, see TaskCallback and add_callback().

property properties

Type:

dict[str, Property]

The registered properties

property type

Type:

str

The name associated to the type of an object