计数+识别两个字符串向量中的常用词 [R]

Question

如何编写一个 R function 可以采用两个字符串向量并返回常用词的数量以及哪些常用词比较元素 1 从 stringvec1 到 stringvec2 的元素 1、strinvec1 的元素 2 到 stringvec2 的元素 2，等等。

假设我有这些数据：

#string vector 1
strvec1 <- c("Griffin Rahea Petersen Deana Franks Morgan","Story Keisha","Douglas Landon Lark","Kinsman Megan Thrall Michael Michels Breann","Gutierrez Mccoy Tyler Westbrook Grayson Swank Shirley Didas Moriah")

#string vector 2
strvec2 <- c("Griffin Morgan Rose Manuel","Van De Grift Sarah Sell William","Mark Landon Lark","Beerman Carlee Megan Thrall Michels","Mcmillan Tyler Jonathan Westbrook Grayson Didas Lloyd Connor")

理想情况下，我有一个 function 会返回常用词的数量以及常用词是什么：

#Non working sample of how functions would ideally work
desiredfunction_numwords(strvec1,strvec2)
[1] 2 0 2 3 4

desiredfunction_matchwords(strvec1,strvec2)
[1] "Griffin Morgan" "" "Landon Lark" "Megan Thrall Michels" "Tyler Westbrook Grayson Didas"

Answer 1

您可以在每个单词处拆分字符串并执行操作。

在基础 R 中：

numwords <- function(str1, str2) {
  mapply(function(x, y) length(intersect(x, y)), 
         strsplit(str1, ' '), strsplit(str2, ' '))
}

matchwords <- function(str1, str2) {
  mapply(function(x, y) paste0(intersect(x, y),collapse = " "), 
         strsplit(str1, ' '), strsplit(str2, ' '))
}

numwords(strvec1, strvec2)
#[1] 2 0 2 3 4

matchwords(strvec1, strvec2)
#[1] "Griffin Morgan"          ""                "Landon Lark"                  
#[4] "Megan Thrall Michels"          "Tyler Westbrook Grayson Didas"

Answer 2

您可以将strvec1用作正则表达式模式，方法是将strsplit分成单独的单词并将单词与交替标记| paste一起使用。 ：

pattern <- paste0(unlist(strsplit(strvec1, " ")), collapse = "|")

您可以将此模式与str_count和str_extract_all使用：

library(stringr) 
# counts:
str_count(strvec2, pattern)
[1] 2 0 2 3 4

# matches:
str_extract_all(strvec2, pattern)
[[1]]
[1] "Griffin" "Morgan" 

[[2]]
character(0)

[[3]]
[1] "Landon" "Lark"  

[[4]]
[1] "Megan"   "Thrall"  "Michels"

[[5]]
[1] "Tyler"     "Westbrook" "Grayson"   "Didas"