easyr1/examples/reward_function/math.py

# Copyright 2024 Bytedance Ltd. and/or its affiliates
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
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import re
from typing import Dict, List

from mathruler.grader import extract_boxed_content, grade_answer


def format_reward(predict: str) -> float:
    pattern = re.compile(r"<think>.*</think>.*\\boxed\{.*\}.*", re.DOTALL)
    format_match = re.fullmatch(pattern, predict)
    return 1.0 if format_match else 0.0


def accuracy_reward(predict: str, ground_truth: str) -> float:
    answer = extract_boxed_content(predict)
    return 1.0 if grade_answer(answer, ground_truth) else 0.0


def compute_score(predicts: List[str], ground_truths: List[str], format_weight: float = 0.1) -> List[Dict[str, float]]:
    scores = []
    for predict, ground_truth in zip(predicts, ground_truths):
        predict = re.sub(r"\s*(<|>|/)\s*", r"\1", predict)  # handle qwen2.5vl-32b format
        format_score = format_reward(predict)
        accuracy_score = accuracy_reward(predict, ground_truth)
        scores.append(
            {
                "overall": (1 - format_weight) * accuracy_score + format_weight * format_score,
                "format": format_score,
                "accuracy": accuracy_score,
            }
        )

    return scores