"""Objective: *the* metric a problem ranks on, with a direction.
Metrics are pure functions (see :mod:`emflow.problems.metrics`); an Objective
is the one a leaderboard sorts by — it adds direction (``lower_is_better``)
and comparison helpers. This is what rebase-hillclimb's ``val_score:`` line
ultimately reports.
"""
from __future__ import annotations
from dataclasses import dataclass
import typing as t
from .metrics import (
Metric,
MeanAbsoluteError,
MeanAbsolutePercentageError,
MeanSquaredError,
PeakTimingError,
PinballLoss,
RootMeanSquaredError,
)
__all__ = [
"Objective", "Metric", "MeanAbsoluteError", "MeanSquaredError",
"RootMeanSquaredError", "MeanAbsolutePercentageError", "PinballLoss",
"PeakTimingError",
]
[docs]
@dataclass
class Objective:
metric: Metric
lower_is_better: bool = True
@property
def name(self) -> str:
return self.metric.name
[docs]
def calculate(self, y_true, y_pred) -> float:
return self.metric.calculate(y_true, y_pred)
[docs]
def elementwise(self, y_true, y_pred):
return self.metric.elementwise(y_true, y_pred)
[docs]
def is_better(self, a: float, b: float) -> bool:
"""True if score ``a`` beats score ``b``."""
return a < b if self.lower_is_better else a > b