feat: add abstract base class of metric (#157)

Signed-off-by: ktro2828 <kotaro.uetake@tier4.jp>

Author: ktro2828

t4_devkit/evaluation/metric/ap.py

@@ -5,13 +5,15 @@
 import numpy as np
 from attrs import define, field
 
+from .base import BaseMetric
+
 if TYPE_CHECKING:
     from t4_devkit.evaluation import BoxMatch, FrameBoxMatch, MatchingScorerLike
 
 __all__ = ["Ap", "ApH"]
 
 
-class Ap:
+class Ap(BaseMetric):
     num_recall_point = 101
     min_precision = 0.1
     min_recall = 0.1

t4_devkit/evaluation/metric/base.py

@@ -0,0 +1,14 @@
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from t4_devkit.evaluation import FrameBoxMatch
+
+
+class BaseMetric(ABC):
+    @abstractmethod
+    def __call__(self, frames: list[FrameBoxMatch]) -> float:
+        """Compute metric score."""
+        ...

t4_devkit/evaluation/metric/clear.py

@@ -4,13 +4,15 @@
 
 from attrs import define, field
 
+from .base import BaseMetric
+
 if TYPE_CHECKING:
     from t4_devkit.evaluation import BoxMatch, FrameBoxMatch, MatchingScorerLike
 
 __all__ = ["Mota", "Motp"]
 
 
-class Mota:
+class Mota(BaseMetric):
     @define
     class ClearBuffer:
         num_gt: int = field(init=False, default=0)