Source code for ontolearn.quality_funcs

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from typing import Set
from owlapy.class_expression import OWLClassExpression
from ontolearn.abstracts import EncodedLearningProblem, AbstractScorer, AbstractKnowledgeBase
from ontolearn.metrics import F1 as _F1, Accuracy as _Accuracy
from ontolearn.search import EvaluatedConcept


def _tp_tn_fp_fn(individuals: Set, pos: Set, neg: Set):
    assert isinstance(individuals, set)
    assert isinstance(pos, set)
    assert isinstance(neg, set)

    tp = len(pos.intersection(individuals))
    tn = len(neg.difference(individuals))
    fp = len(neg.intersection(individuals))
    fn = len(pos.difference(individuals))
    return tp, tn, fp, fn


[docs] def f1(*, individuals: Set, pos: Set, neg: Set): tp, tn, fp, fn = _tp_tn_fp_fn(individuals, pos, neg) applicable, score = _F1().score2(tp=tp, fn=fn, fp=fp, tn=tn) return score if applicable else 0
[docs] def acc(*, individuals: Set, pos: Set, neg: Set): tp, tn, fp, fn = _tp_tn_fp_fn(individuals, pos, neg) _, score = _Accuracy().score2(tp=tp, fn=fn, fp=fp, tn=tn) return score
[docs] def evaluate_concept(kb: AbstractKnowledgeBase, concept: OWLClassExpression, quality_func: AbstractScorer, encoded_learning_problem: EncodedLearningProblem) -> EvaluatedConcept: """Evaluates a concept by using the encoded learning problem examples, in terms of Accuracy or F1-score. Note: This method is useful to tell the quality (e.q) of a generated concept by the concept learners, to get the set of individuals (e.inds) that are classified by this concept and the amount of them (e.ic). Args: kb: The knowledge base where to evaluate the concept. concept: The concept to be evaluated. quality_func: Quality measurement in terms of Accuracy or F1-score. encoded_learning_problem: The encoded learning problem. Return: The evaluated concept. """ e = EvaluatedConcept() e.inds = kb.individuals_set(concept) e.ic = len(e.inds) _, e.q = quality_func.score_elp(e.inds, encoded_learning_problem) return e