Tuning BM25 One of the nice features of BM25 is that, unlike TF/IDF, it has two parameters that allow it to be tuned: k1 This parameter controls how quickly an increase in term frequency results in term-frequency saturation. The default value is 1.2.…
Pluggable Similarity Algorithms Before we move on from relevance and scoring, we will finish this chapter with a more advanced subject: pluggable similarity algorithms. While Elasticsearch uses the Lucene’s Practical Scoring Function as its default s…
设置n为字符串s的长度.("我是个小仙女") 设置m为字符串t的长度.("我不是个小仙女") 如果n等于0,返回m并退出.如果m等于0,返回n并退出.构造两个向量v0[m+1] 和v1[m+1],串联0..m之间所有的元素. 2 初始化 v0 to 0..m. 3 检查 s (i from 1 to n) 中的每个字符. 4 检查 t (j from 1 to m) 中的每个字符 5 如果 s[i] 等于 t[j],则编辑代价cost为 0:如果 s[i] 不等于…
一.词项相似度 elasticsearch支持拼写纠错,其建议词的获取就需要进行词项相似度的计算:今天我们来通过不同的距离算法来学习一下词项相似度算法: 二.数据准备 计算词项相似度,就需要首先将词项向量化:我们可以使用以下两种方法 字符向量化,其将每个字符映射为一个唯一的数字,我们可以直接使用字符编码即可: import numpy as np def vectorize_words(words): lower_words = [word.lower() for word in words]…
similarity Elasticsearch allows you to configure a scoring algorithm or similarity per field. The similaritysetting provides a simple way of choosing a similarity algorithm other than the default BM25, such as TF/IDF. Similarities are mostly useful f…
