Using PenaltyModel Factories

penaltymodel provides functionality for accessing PenaltyModel factories.

Accessing Factories

Any factories that have been identified through the FACTORY_ENTRYPOINT entrypoint and installed on the python path can be accessed through the get_penalty_model() function.

Examples

>>> import networkx as nx
>>> import dimod
>>> graph = nx.path_graph(5)
>>> decision_variables = (0, 4)  # the ends of the path
>>> feasible_configurations = {(-1, -1), (1, 1)}  # we want the ends of the path to agree
>>> spec = pm.Specification(graph, decision_variables, feasible_configurations, dimod.SPIN)
>>> widget = pm.get_penalty_model(spec)

Functions and Utilities

FACTORY_ENTRYPOINT = 'penaltymodel_factory'

constant used when assigning entrypoints for factories.

Type:str
CACHE_ENTRYPOINT = 'penaltymodel_cache'

constant used when assigning entrypoints for caches.

Type:str
get_penalty_model(specification)[source]

Retrieve a PenaltyModel from one of the available factories.

Parameters:specification (Specification) – The specification for the desired PenaltyModel.
Returns:A PenaltyModel as returned by the highest priority factory, or None if no factory could produce it.
Return type:PenaltyModel/None
Raises:ImpossiblePenaltyModel – If the specification describes a penalty model that cannot be built by any factory.
penaltymodel_factory(priority)[source]

Decorator to assign a priority attribute to the decorated function.

Parameters:priority (int) – The priority of the factory. Factories are queried in order of decreasing priority.

Examples

Decorate penalty model factories like:

>>> @pm.penaltymodel_factory(105)
... def factory_function(spec):
...     pass
>>> factory_function.priority
105
iter_factories()[source]

Iterate through all factories identified by the factory entrypoint.

Yields:function – A function that accepts a Specification and returns a PenaltyModel.
iter_caches()[source]

Iterator over the PenaltyModel caches.

Yields:function – A function that accepts a PenaltyModel and caches it.

Exceptions

exception FactoryException[source]

General exception for a factory being not able to produce a penalty model.

exception ImpossiblePenaltyModel[source]

PenaltyModel is impossible to build.

exception MissingPenaltyModel[source]

PenaltyModel is missing from the cache or otherwise unavailable.