paref.pareto_reflection_sequences.generic.next_when_stopping_criteria_met

Classes

NextWhenStoppingCriteriaMet(...)

Define a sequence by moving on to the next Pareto reflection if convergence is reached

class paref.pareto_reflection_sequences.generic.next_when_stopping_criteria_met.NextWhenStoppingCriteriaMet(pareto_reflections: List[ParetoReflection], stopping_criteria: StoppingCriteria)

Bases: SequenceParetoReflections

Define a sequence by moving on to the next Pareto reflection if convergence is reached

When to use

This sequence should be used if you want to repeat a single Pareto reflection until the Pareto point it is looking for is sufficiently close approximated (to be specified in a stopping criteria).

What it does

The sequence simply loops through given Pareto reflections until a defined stopping criteria is met. If the end is reached, this sequence returns None, indicating the end of the sequence.

Examples

# TBA: add Initialize list of Pareto reflections

>>> import numpy as np
>>> from paref.pareto_reflections.restrict_by_point import RestrictByPoint
>>> from paref.pareto_reflection_sequences.generic.repeating_sequence import RepeatingSequence
>>> from paref.moo_algorithms.stopping_criteria.max_iterations_reached import MaxIterationsReached

Initialze stopping criteria

>>> stopping_criteria = MaxIterationsReached(max_iterations=1)

Initialize Pareto reflection to be repeated

>>> pareto_reflecting_functions = [RestrictByPoint(nadir=np.ones(1),restricting_point=np.ones(1))]

Initialize repeating sequence

>>> sequence = RepeatingSequence(pareto_reflections=pareto_reflecting_functions)

The repeating sequence returns the given Pareto reflection in each step of iteration until the stopping criteria is met

>>> sequence.next().__class__.__name__
RestrictByPoint

>>> sequence.next()
None

Specify the stopping criteria and the Pareto reflections to be repeated

param stopping_criteria:

stopping criteria indicating when to move to the next Pareto reflection

type stopping_criteria:

StoppingCriteria

param pareto_reflections:

Pareto reflections stored in a list

type pareto_reflections:

List[ParetoReflection]

next(blackbox_function: BlackboxFunction) → ParetoReflection | None

Return the next Pareto reflection of the sequence if stopping criteria is met

Returns:

next Pareto reflection of the list or same Pareto reflection as before if stopping criteria is not met

Return type:

ParetoReflection