Timeline

Definition of main Timeline class.

This module defines the Timeline class, which provides an interface for the simulation kernel and drives event execution. All entities are required to have an attached timeline for simulation.

class sequence.kernel.timeline.Timeline(stop_time: int = 100000000000000000000000, formalism: str = None, truncation: int = 1)

Class for a simulation timeline.

Timeline holds entities, which are configured before the simulation. Before the start of simulation, the timeline must initialize all controlled entities. The initialization of entities may schedule events. The timeline pushes these events to its event list. The timeline starts simulation by popping the top event in the event list repeatedly. The time of popped event becomes current simulation time of the timeline. The process of popped event is executed. The simulation stops if the timestamp on popped event is equal or larger than the stop time, or if the eventlist is empty.

To monitor the progress of simulation, the Timeline.show_progress attribute can be modified to show/hide a progress bar.

events

the event list of timeline.

Type:: EventList

entities

the entity list of timeline used for initialization.

Type:: list[Entity]

time

current simulation time (picoseconds). The smallest amount of time in the simulation timeline is 1 picosecond

Type:: int

stop_time

the stop (simulation) time of the simulation.

Type:: int

schedule_counter

the counter of scheduled events

Type:: int

run_counter

the counter of executed events

Type:: int

is_running

records if the simulation has stopped executing events.

Type:: bool

show_progress

show/hide the progress bar of simulation.

Type:: bool

quantum_manager

quantum state manager.

Type:: QuantumManager

init() → None: Method to initialize all simulated entities.

now() → int: Returns current simulation time.

static ns_to_human_time(nanoseconds: float) → str: Returns a string in the form [D day[s], ][H]H:MM:SS[.UUUUUU]

progress_bar()

Method to draw progress bar.

Progress bar will display the execution time of simulation, as well as the current simulation time.

remove_event(event: Event) → None: Remove an event from the event list

run() → None

Main simulation method.

The run method begins simulation of events. Events are continuously popped and executed, until the simulation time limit is reached or events are exhausted. A progress bar may also be displayed, if the show_progress flag is set.

schedule(event: Event) → None: Method to schedule an event.

static seed(seed: int) → None: Sets random seed for simulation.

stop() → None: Method to stop simulation.

update_event_time(event: Event, time: int) → None

Method to change execution time of an event.

Parameters:

event (Event) – event to reschedule.
time (int) – new simulation time (should be >= current time).