paddlenlp.metrics.chunk 源代码

# Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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from collections import defaultdict

import numpy as np
import paddle
from paddlenlp.utils.log import logger
from seqeval.metrics.sequence_labeling import get_entities

def extract_tp_actual_correct(y_true, y_pred, suffix, *args):
    entities_true = defaultdict(set)
    entities_pred = defaultdict(set)
    for type_name, start, end in get_entities(y_true, suffix):
        entities_true[type_name].add((start, end))
    for type_name, start, end in get_entities(y_pred, suffix):
        entities_pred[type_name].add((start, end))

    target_names = sorted(set(entities_true.keys()) | set(entities_pred.keys()))

    tp_sum = np.array([], dtype=np.int32)
    pred_sum = np.array([], dtype=np.int32)
    true_sum = np.array([], dtype=np.int32)
    for type_name in target_names:
        entities_true_type = entities_true.get(type_name, set())
        entities_pred_type = entities_pred.get(type_name, set())
        tp_sum = np.append(tp_sum, len(entities_true_type & entities_pred_type))
        pred_sum = np.append(pred_sum, len(entities_pred_type))
        true_sum = np.append(true_sum, len(entities_true_type))

    return pred_sum, tp_sum, true_sum

[文档]class ChunkEvaluator(paddle.metric.Metric): """ ChunkEvaluator computes the precision, recall and F1-score for chunk detection. It is often used in sequence tagging tasks, such as Named Entity Recognition(NER). Args: label_list (list): The label list. suffix (bool): If set True, the label ends with '-B', '-I', '-E' or '-S', else the label starts with them. Defaults to `False`. Example: .. code-block:: from paddlenlp.metrics import ChunkEvaluator num_infer_chunks = 10 num_label_chunks = 9 num_correct_chunks = 8 label_list = [1,1,0,0,1,0,1] evaluator = ChunkEvaluator(label_list) evaluator.update(num_infer_chunks, num_label_chunks, num_correct_chunks) precision, recall, f1 = evaluator.accumulate() print(precision, recall, f1) # 0.8 0.8888888888888888 0.8421052631578948 """ def __init__(self, label_list, suffix=False): super(ChunkEvaluator, self).__init__() self.id2label_dict = dict(enumerate(label_list)) self.suffix = suffix self.num_infer_chunks = 0 self.num_label_chunks = 0 self.num_correct_chunks = 0
[文档] def compute(self, lengths, predictions, labels, dummy=None): """ Computes the precision, recall and F1-score for chunk detection. Args: lengths (Tensor): The valid length of every sequence, a tensor with shape `[batch_size]` predictions (Tensor): The predictions index, a tensor with shape `[batch_size, sequence_length]`. labels (Tensor): The labels index, a tensor with shape `[batch_size, sequence_length]`. dummy (Tensor, optional): Unnecessary parameter for compatibility with older versions with parameters list `inputs`, `lengths`, `predictions`, `labels`. Defaults to None. Returns: tuple: Returns tuple (`num_infer_chunks, num_label_chunks, num_correct_chunks`). With the fields: - `num_infer_chunks` (Tensor): The number of the inference chunks. - `num_label_chunks` (Tensor): The number of the label chunks. - `num_correct_chunks` (Tensor): The number of the correct chunks. """ if dummy is not None: # TODO(qiujinxuan): rm compatibility support after lic. dummy, lengths, predictions, labels = lengths, predictions, labels, dummy if not getattr(self, "has_warn", False): logger.warning( "Compatibility Warning: The params of ChunkEvaluator.compute has been modified. The old version is `inputs`, `lengths`, `predictions`, `labels` while the current version is `lengths`, `predictions`, `labels`. Please update the usage." ) self.has_warn = True labels = labels.numpy() predictions = predictions.numpy() unpad_labels = [ [self.id2label_dict[index] for index in labels[sent_index][: lengths[sent_index]]] for sent_index in range(len(lengths)) ] unpad_predictions = [ [self.id2label_dict.get(index, "O") for index in predictions[sent_index][: lengths[sent_index]]] for sent_index in range(len(lengths)) ] pred_sum, tp_sum, true_sum = extract_tp_actual_correct(unpad_labels, unpad_predictions, self.suffix) num_correct_chunks = paddle.to_tensor([tp_sum.sum()]) num_infer_chunks = paddle.to_tensor([pred_sum.sum()]) num_label_chunks = paddle.to_tensor([true_sum.sum()]) return num_infer_chunks, num_label_chunks, num_correct_chunks
def _is_number_or_matrix(self, var): def _is_number_(var): return ( isinstance(var, int) or isinstance(var, np.int64) or isinstance(var, float) or (isinstance(var, np.ndarray) and var.shape == (1,)) ) return _is_number_(var) or isinstance(var, np.ndarray)
[文档] def update(self, num_infer_chunks, num_label_chunks, num_correct_chunks): """ This function takes (num_infer_chunks, num_label_chunks, num_correct_chunks) as input, to accumulate and update the corresponding status of the ChunkEvaluator object. The update method is as follows: .. math:: \\\\ \\begin{array}{l}{\\text { self. num_infer_chunks }+=\\text { num_infer_chunks }} \\\\ {\\text { self. num_Label_chunks }+=\\text { num_label_chunks }} \\\\ {\\text { self. num_correct_chunks }+=\\text { num_correct_chunks }}\\end{array} \\\\ Args: num_infer_chunks(int|numpy.array): The number of chunks in Inference on the given minibatch. num_label_chunks(int|numpy.array): The number of chunks in Label on the given mini-batch. num_correct_chunks(int|float|numpy.array): The number of chunks both in Inference and Label on the given mini-batch. """ if not self._is_number_or_matrix(num_infer_chunks): raise ValueError("The 'num_infer_chunks' must be a number(int) or a numpy ndarray.") if not self._is_number_or_matrix(num_label_chunks): raise ValueError("The 'num_label_chunks' must be a number(int, float) or a numpy ndarray.") if not self._is_number_or_matrix(num_correct_chunks): raise ValueError("The 'num_correct_chunks' must be a number(int, float) or a numpy ndarray.") self.num_infer_chunks += num_infer_chunks self.num_label_chunks += num_label_chunks self.num_correct_chunks += num_correct_chunks
[文档] def accumulate(self): """ This function returns the mean precision, recall and f1 score for all accumulated minibatches. Returns: tuple: Returns tuple (`precision, recall, f1 score`). """ precision = float(self.num_correct_chunks / self.num_infer_chunks) if self.num_infer_chunks else 0.0 recall = float(self.num_correct_chunks / self.num_label_chunks) if self.num_label_chunks else 0.0 f1_score = float(2 * precision * recall / (precision + recall)) if self.num_correct_chunks else 0.0 return precision, recall, f1_score
[文档] def reset(self): """ Reset function empties the evaluation memory for previous mini-batches. """ self.num_infer_chunks = 0 self.num_label_chunks = 0 self.num_correct_chunks = 0
[文档] def name(self): """ Return name of metric instance. """ return "precision", "recall", "f1"