"""Quality metrics for concept learners."""
from typing import Final, Tuple
from .abstracts import AbstractScorer
[docs]
class Recall(AbstractScorer):
"""Recall quality function.
Attribute:
name: name of the metric = 'Recall'.
"""
__slots__ = ()
name: Final = 'Recall'
[docs]
def score2(self, tp: int, fn: int, fp: int, tn: int) -> Tuple[bool, float]:
try:
recall = tp / (tp + fn)
return True, round(recall, 5)
except ZeroDivisionError:
return False, 0
[docs]
class Precision(AbstractScorer):
"""Precision quality function.
Attribute:
name: name of the metric = 'Precision'.
"""
__slots__ = ()
name: Final = 'Precision'
[docs]
def score2(self, tp: int, fn: int, fp: int, tn: int) -> Tuple[bool, float]:
try:
precision = tp / (tp + fp)
return True, round(precision, 5)
except ZeroDivisionError:
return False, 0
[docs]
class F1(AbstractScorer):
"""F1-score quality function.
Attribute:
name: name of the metric = 'F1'.
"""
__slots__ = ()
name: Final = 'F1'
[docs]
def score2(self, tp: int, fn: int, fp: int, tn: int) -> Tuple[bool, float]:
try:
recall = tp / (tp + fn)
except ZeroDivisionError:
return False, 0
try:
precision = tp / (tp + fp)
except ZeroDivisionError:
return False, 0
if precision == 0 or recall == 0:
return False, 0
f_1 = 2 * ((precision * recall) / (precision + recall))
return True, round(f_1, 5)
[docs]
class Accuracy(AbstractScorer):
"""
Accuracy quality function.
Accuracy is acc = (tp + tn) / (tp + tn + fp+ fn).
However, Concept learning papers (e.g. Learning OWL Class expression) appear to invent their own accuracy metrics.
In OCEL => Accuracy of a concept = 1 - ( \\|E^+ \\ R(C)\\|+ \\|E^- AND R(C)\\|) / \\|E\\|).
In CELOE => Accuracy of a concept C = 1 - ( \\|R(A) \\ R(C)\\| + \\|R(C) \\ R(A)\\|)/n.
1) R(.) is the retrieval function, A is the class to describe and C in CELOE.
2) E^+ and E^- are the positive and negative examples probided. E = E^+ OR E^- .
Attribute:
name: name of the metric = 'Accuracy'.
"""
__slots__ = ()
name: Final = 'Accuracy'
[docs]
def score2(self, tp: int, fn: int, fp: int, tn: int) -> Tuple[bool, float]:
acc = (tp + tn) / (tp + tn + fp + fn)
# acc = 1 - ((fp + fn) / len(self.pos) + len(self.neg)) # from Learning OWL Class Expressions.
return True, round(acc, 5)
[docs]
class WeightedAccuracy(AbstractScorer):
"""
WeightedAccuracy quality function.
Attribute:
name: name of the metric = 'WeightedAccuracy'.
"""
__slots__ = ()
name: Final = 'WeightedAccuracy'
[docs]
def score2(self, tp: int, fn: int, fp: int, tn: int) -> Tuple[bool, float]:
ap = tp + fn
an = fp + tn
wacc = ((tp/ap) + (tn/an)) / ((tp/ap) + (tn/an) + (fp/an) + (fn/ap))
return True, round(wacc, 5)