EditDistance¶
用于管理字符串的编辑距离。编辑距离是通过计算将一个字符串转换为另一个字符串所需的最小编辑操作数（添加、删除或替换）来量化两个字符串（例如单词）彼此不相似的程度一种方法。参考 https://en.wikipedia.org/wiki/Edit_distance。
代码示例¶
import paddle.fluid as fluid
import numpy as np
# suppose that batch_size is 128
batch_size = 128
# init the edit distance manager
distance_evaluator = fluid.metrics.EditDistance("EditDistance")
# generate the edit distance across 128 sequence pairs, the max distance is 10 here
edit_distances_batch0 = np.random.randint(low = 0, high = 10, size = (batch_size, 1))
seq_num_batch0 = batch_size
distance_evaluator.update(edit_distances_batch0, seq_num_batch0)
avg_distance, wrong_instance_ratio = distance_evaluator.eval()
print("the average edit distance for batch0 is %.2f and the wrong instance ratio is %.2f " % (avg_distance, wrong_instance_ratio))
edit_distances_batch1 = np.random.randint(low = 0, high = 10, size = (batch_size, 1))
seq_num_batch1 = batch_size
distance_evaluator.update(edit_distances_batch1, seq_num_batch1)
avg_distance, wrong_instance_ratio = distance_evaluator.eval()
print("the average edit distance for batch0 and batch1 is %.2f and the wrong instance ratio is %.2f " % (avg_distance, wrong_instance_ratio))
distance_evaluator.reset()
edit_distances_batch2 = np.random.randint(low = 0, high = 10, size = (batch_size, 1))
seq_num_batch2 = batch_size
distance_evaluator.update(edit_distances_batch2, seq_num_batch2)
avg_distance, wrong_instance_ratio = distance_evaluator.eval()
print("the average edit distance for batch2 is %.2f and the wrong instance ratio is %.2f " % (avg_distance, wrong_instance_ratio))