BrianObject class

(Shortest import: from brian2 import BrianObject)

class brian2.core.base.BrianObject(*args, **kw)

Bases: Nameable

All Brian objects derive from this class, defines magic tracking and update.

See the documentation for Network for an explanation of which objects get updated in which order.

Parameters:

dt : Quantity, optional

The time step to be used for the simulation. Cannot be combined with the clock argument.

clock : Clock, optional

The update clock to be used. If neither a clock, nor the dt argument is specified, the defaultclock will be used.

when : str, optional

In which scheduling slot to simulate the object during a time step. Defaults to 'start'. See Scheduling for possible values.

order : int, optional

The priority of this object for operations occurring at the same time step and in the same scheduling slot. Defaults to 0.

namespace: dict, optional :

A dictionary mapping identifier names to objects. If not given, the namespace will be filled in at the time of the call of Network.run, with either the values from the namespace argument of the Network.run method or from the local context, if no such argument is given.

name : str, optional

A unique name for the object - one will be assigned automatically if not provided (of the form brianobject_1, etc.).

Notes :

—– :

The set of all `BrianObject` objects is stored in ``BrianObject.__instances__()``. :

Attributes

_clock	The clock used for simulating this object
_creation_stack	A string indicating where this object was created (traceback with any parts of Brian code removed)
_network	Used to remember the Network in which this object has been included before, to raise an error if it is included in a new Network
_scope_current_key	Global key value for ipython cell restrict magic
_scope_key	The scope key is used to determine which objects are collected by magic
active	Whether or not the object should be run.
add_to_magic_network	Whether or not the object should be added to a MagicNetwork.
clock	The Clock determining when the object should be updated.
code_objects	The list of CodeObject contained within the BrianObject.
contained_objects	The list of objects contained within the BrianObject.
invalidates_magic_network	Whether or not MagicNetwork is invalidated when a new BrianObject of this type is added
name	The unique name for this object.
namespace	The group-specific namespace
order	The order in which objects with the same clock and when should be updated
updaters	The list of Updater that define the runtime behaviour of this object.
when	The ID string determining when the object should be updated in Network.run.

Methods

add_dependency(obj)	Add an object to the list of dependencies.
after_run()	Optional method to do work after a run is finished.
before_run(run_namespace)	Optional method to prepare the object before a run.
run()

Details

_clock

The clock used for simulating this object

_creation_stack

A string indicating where this object was created (traceback with any parts of Brian code removed)

_network

Used to remember the Network in which this object has been included before, to raise an error if it is included in a new Network

_scope_current_key

Global key value for ipython cell restrict magic

_scope_key

The scope key is used to determine which objects are collected by magic

active

Whether or not the object should be run.

Inactive objects will not have their update method called in Network.run. Note that setting or unsetting the active attribute will set or unset it for all contained_objects.

add_to_magic_network

Whether or not the object should be added to a MagicNetwork. Note that all objects in BrianObject.contained_objects are automatically added when the parent object is added, therefore e.g. NeuronGroup should set add_to_magic_network to True, but it should not be set for all the dependent objects such as StateUpdater

clock

The Clock determining when the object should be updated.

Note that this cannot be changed after the object is created.

code_objects

The list of CodeObject contained within the BrianObject.

TODO: more details.

Note that this attribute cannot be set directly, you need to modify the underlying list, e.g. obj.code_objects.extend([A, B]).

contained_objects

The list of objects contained within the BrianObject.

When a BrianObject is added to a Network, its contained objects will be added as well. This allows for compound objects which contain a mini-network structure.

Note that this attribute cannot be set directly, you need to modify the underlying list, e.g. obj.contained_objects.extend([A, B]).

invalidates_magic_network

Whether or not MagicNetwork is invalidated when a new BrianObject of this type is added

name

The unique name for this object.

Used when generating code. Should be an acceptable variable name, i.e. starting with a letter character and followed by alphanumeric characters and _.

namespace

The group-specific namespace

order

The order in which objects with the same clock and when should be updated

updaters

The list of Updater that define the runtime behaviour of this object.

TODO: more details.

Note that this attribute cannot be set directly, you need to modify the underlying list, e.g. obj.updaters.extend([A, B]).

when

The ID string determining when the object should be updated in Network.run.

add_dependency(obj)

Add an object to the list of dependencies. Takes care of handling subgroups correctly (i.e., adds its parent object).

Parameters:

obj : BrianObject

The object that this object depends on.

after_run()

Optional method to do work after a run is finished.

Called by Network.after_run after the main simulation loop terminated.

before_run(run_namespace)

Optional method to prepare the object before a run.

Called by Network.after_run before the main simulation loop starts.

run()