字符串匹配两个向量到文本的限制由两者之间的距离限制

Question

我试图找出最有效的方法来匹配两个字符串向量到第三个字符串。 我希望将第二场比赛限制在距离第一场比赛的有限数量的单词或字符之外

假设我有一个像这样的名字数据框：

signers <- data.frame(
    first = 
        c("Benjamin","Thomas","Robert","George","Thomas","Jared","James","John","James","George","George","James","Edmund","George") ,
    last = 
        c( "Franklin","Mifflin","Morris","Clymer","Fitzsimons","Ingersoll","Wilson","Blair","Madison","Washington","Mason","McClurg","Randolph","Wythe")
    )

我有一些这样的文字：

    text <- 
"A lot of people attended the Constitutional Convention in Philadephia, including Alexander Hamilton, Benjamin Franklin and John Adams.  
Not everyone who attended the convention ended up signing the Constitution, including George Wythe, John F. Mercer and Edmund Jennings Randolph who abstained."

我想在“签名者”数据框中搜索每个名称，并标记它们是否在文本中。

在本杰明富兰克林和乔治威斯的情况下，名字正好在文中。 在Edmund Randolph的案例中，他的名字和姓氏之间有一个或10个字符。

所以我正在寻找这样的东西：

      first       last      inparagraph
1  Benjamin   Franklin      1
2    Thomas    Mifflin
3    Robert     Morris
4    George     Clymer
5    Thomas Fitzsimons
6     Jared  Ingersoll
7     James     Wilson
8      John      Blair
9     James    Madison
10   George Washington
11   George      Mason
12    James    McClurg
13   Edmund   Randolph      1
14   George      Wythe      1

我虽然使用lappy函数来查找名字所在的位置，但我不确定如何在第一个名字所在的位置附近进行搜索。

namesfinds <- lapply( signers$first ,  grep, text )

Answer 1

这是一个选项，允许使用正则表达式在名字和姓氏之间最多三个单词或首字母：

patterns <- paste0("(.*)(", signers$first, "(\\s+[[:alpha:].]+){,3}\\s+", signers$last, ")(.*)")
signers$inparagraph <- ifelse(sapply(patterns, grepl, text), "1", "")

生产：

      first       last inparagraph
1  Benjamin   Franklin           1
2    Thomas    Mifflin            
3    Robert     Morris            
4    George     Clymer            
5    Thomas Fitzsimons            
6     Jared  Ingersoll            
7     James     Wilson            
8      John      Blair           1
9     James    Madison            
10   George Washington            
11   George      Mason            
12    James    McClurg            
13   Edmund   Randolph           1
14   George      Wythe           1

请注意John Blair匹配，因为我修改了text以进行测试以包含他（请参阅下面的数据）。 如果您想允许更少的单词，您可以将{,3}更改为更低的数字。 现在，如果您想要实际提取匹配的名称，您可以：

unname(sapply(patterns, gsub, "\\2", text))[sapply(patterns, grepl, text)]
# [1] "Benjamin Franklin"        "John W. F. Blair"         "Edmund Jennings Randolph"
# [4] "George Wythe"     

这是我用过的text ：

text <- 
  "A lot of people attended the Constitutional Convention in Philadephia, including Alexander Hamilton, Benjamin Franklin and John Adams.  
Not everyone who attended the convention ended up signing the Constitution, including George Wythe, John F. Mercer and Edmund Jennings Randolph who abstained and John W. F. Blair ate cake"

Answer 2

它可能不漂亮，但这似乎有效。 将正则表达式粘贴在一起以捕捉中间名是我使用的技巧。 看起来它适用于任何名称。 希望它适用于您的所有数据。

> a <- paste(signers[,1], signers[,2])
> pst <- paste(signers$first, ".*", signers$last, sep = "")
> gg <- gsub("\\.\\*", " ", names(unlist(sapply(pst, grep, text))))
> signers$inparagraph <- ifelse(a %in% gg, "1", "")
> signers
##       first       last inparagraph
## 1  Benjamin   Franklin           1
## 2    Thomas    Mifflin           
## 3    Robert     Morris           
## 4    George     Clymer           
## 5    Thomas Fitzsimons           
## 6     Jared  Ingersoll           
## 7     James     Wilson           
## 8      John      Blair           
## 9     James    Madison           
## 10   George Washington           
## 11   George      Mason           
## 12    James    McClurg           
## 13   Edmund   Randolph           1
## 14   George      Wythe           1