bellini.laws.Law

class bellini.laws.Law(law_fn, input_mapping, output_labels=None, name=None, params=None, group_create_fn=None)[source]

Bases: object

An object that applies some physical law on a group, grabbing inputs dictated by input_mapping, applying law_fn, and returning a new instance with the law applied.

__init__(law_fn, input_mapping, output_labels=None, name=None, params=None, group_create_fn=None)[source]
Parameters

  • law_fn (Python callable) – a function that takes kwarg inputs based on input_mapping’s labels and returns a dict storing law outputs. the dict should have labels (bellini.Reference) corresponding to the attribute the result will be stored in when the law is applied to an object, and values of those resulting outputs. fn should expected Quantity inputs and must also return Quantity outputs.

  • input_mapping (dict) – a dict mapping law_fn kwarg labels (str) to attributes names (str), which will be used to retrieve inputs from the given group

  • output_labels (list) – output labels of law_fn, which are used to connect inputs and outputs during compilation. this is not necessary if law_fn is written purely using bellini.api.functional calls, which keeps track of transformations automatically, but is required if you perform computation using an accelerated framework e.g. jax, torch

  • params (dict, optional) – parameters of law_fn that do not rely on inputs

  • group_create_fn (Python callable, optional) – a function that takes law_fn’s outputs and the original Group and returns a new Group. If not provided, the returned Group after applying a law will just be a copy of the original group, with new attributes set according to the output of law_fn and/or output_labels

Methods

__init__(law_fn, input_mapping[, …])

Parameters

  • law_fn (Python callable) – a function that takes kwarg inputs based on