从 R 中的字符串向量中匹配单词

Matching words from vectors of strings in R

我正在尝试通过将混乱的站点名称列表与已批准的列表进行匹配来清理数据库。

例如,首选站点名称可能是 'Cotswold Water Park Pit 28',但该站点已作为以下名称输入到数据库中:'Pit 28'、'28'、'CWP Pit 28' 和 'Cotswold 28'.

数据看起来像这样:

approved <- c("Cotswold Water Park Pit 28", "Cotswold Water Park Pit 14", "Robinswood Hill")

messy <- c("Pit 28", "28", "CWP Pit 28", "Cotswold 28", "14", "Robinswood")

我正在寻找一种方法来匹配 messy 中每个元素中的 words/numbers(非 space 字符的簇)与每个元素中的 words/numbers approved 中的元素。理想情况下,我会得到这样的结果:

     Cotswold Water Park Pit 28 Cotswold Water Park Pit 14 Robinswood Hill
[1,] "Pit 28"                   "Pit 28"                   "Robinswood"   
[2,] "28"                       "CWP Pit 28"               NA             
[3,] "CWP Pit 28"               "14"                       NA             
[4,] "Cotswold 28"              NA                         NA   

approved 元素构成列名称,messy 中包含匹配 words/numbers 的任何元素出现在该列的单元格中。我知道会有一些错误的匹配。这很好,我可以稍后手动过滤它们,并可能从模式匹配中排除 'forest' 和 'hill' 等常见词。

通过使用 regex 拆分 messy 中的每个元素,我已经能够使用上述示例数据获得我想要的结果,但随后我正在处理 [=45= 的列表] 从站点名称列表中,我不得不使用嵌套循环或 sapply 将它们与已批准的元素匹配,因为像 grepgrepl 和 [=22= 这样的函数] 只允许一种模式。由于数据库很大,当我将它应用到整个事物时,这已经花费了很长时间。我真正想要的是一个功能:

match(any word in approved[1], any word in messy[1])

要么给我一个 TRUE FALSE 输出,要么提取 messy[1] 如果匹配就太好了!

一个tidyverse/tidytext解决方案

先把它们变成数据框

require(tidyverse) 
require(tidytext)


## create dataframe for approved 

approved <- c("Cotswold Water Park Pit 28", "Cotswold Water Park Pit 14", "Robinswood Hill")


## create dataframe for messy 

messy <- c("Pit 28", "28", "CWP Pit 28", "Cotswold 28", "14", "Robinswood")

然后使用 tidytext 将它们拆分为 1 个字 = 1 行,我喜欢在行数发生变化时添加 ID ...

## split into words 

approved_df <- 
tibble(approved = approved) %>%  
  rownames_to_column('approved_id') %>% 
  unnest_tokens(words, approved, 'words', drop = FALSE)

approved_df %>%  head 

# A tibble: 6 x 3
# approved_id approved                   words   
# <chr>       <chr>                      <chr>   
# 1 1           Cotswold Water Park Pit 28 cotswold
# 2 1           Cotswold Water Park Pit 28 water   
# 3 1           Cotswold Water Park Pit 28 park    
# 4 1           Cotswold Water Park Pit 28 pit     
# 5 1           Cotswold Water Park Pit 28 28      
# 6 2           Cotswold Water Park Pit 14 cotswold
    
messy_df <- 
tibble(messy = messy) %>%  
  rownames_to_column('messy_id') %>% 
  unnest_tokens(words, messy, 'words', drop = FALSE)

messy_df %>%  head          
# # A tibble: 6 x 3
# messy_id messy      words
# <chr>    <chr>      <chr>
# 1 1        Pit 28     pit  
# 2 1        Pit 28     28   
# 3 2        28         28   
# 4 3        CWP Pit 28 cwp  
# 5 3        CWP Pit 28 pit  
# 6 3        CWP Pit 28 28   

最后,将两个dataframes在word级别join,统计重叠的单词有多少,然后给每个“乱七八糟”的字符串分配一个“认可的”

     ## join the data sets and rank by the number of words in the overlap
  
  messy_df %>%  left_join(approved_df) %>%  
    group_by(messy, messy_id, approved, approved_id) %>%  
    summarise(n_row = n()) %>%  
    ungroup %>%  
    group_by(messy, messy_id) %>%  
    mutate(approved_rank = rank(desc(n_row))) %>%  
    ungroup %>%  
    filter(approved_rank == 1) %>%  
    arrange(messy_id)



  # Joining, by = "words"
  # # A tibble: 6 x 6
  # messy       messy_id approved                   approved_id n_row approved_rank
  # <chr>       <chr>    <chr>                      <chr>       <int>         <dbl>
  # 1 Pit 28      1        Cotswold Water Park Pit 28 1               2             1
  # 2 28          2        Cotswold Water Park Pit 28 1               1             1
  # 3 CWP Pit 28  3        Cotswold Water Park Pit 28 1               2             1
  # 4 Cotswold 28 4        Cotswold Water Park Pit 28 1               2             1
  # 5 14          5        Cotswold Water Park Pit 14 2               1             1
  # 6 Robinswood  6        Robinswood Hill            3               1             1

我不确定我下面的尝试是否符合您的目的

res <- within(
  expand.grid(messy, approved),
  matched <- do.call(
    function(...) lengths(mapply(intersect, ...)) > 0,
    unname(expand.grid(strsplit(messy, " "), strsplit(approved, " ")))
  )
)

给予

          Var1                       Var2 matched
1       Pit 28 Cotswold Water Park Pit 28    TRUE
2           28 Cotswold Water Park Pit 28    TRUE
3   CWP Pit 28 Cotswold Water Park Pit 28    TRUE
4  Cotswold 28 Cotswold Water Park Pit 28    TRUE
5           14 Cotswold Water Park Pit 28   FALSE
6   Robinswood Cotswold Water Park Pit 28   FALSE
7       Pit 28 Cotswold Water Park Pit 14    TRUE
8           28 Cotswold Water Park Pit 14   FALSE
9   CWP Pit 28 Cotswold Water Park Pit 14    TRUE
10 Cotswold 28 Cotswold Water Park Pit 14    TRUE
11          14 Cotswold Water Park Pit 14    TRUE
12  Robinswood Cotswold Water Park Pit 14   FALSE
13      Pit 28            Robinswood Hill   FALSE
14          28            Robinswood Hill   FALSE
15  CWP Pit 28            Robinswood Hill   FALSE
16 Cotswold 28            Robinswood Hill   FALSE
17          14            Robinswood Hill   FALSE
18  Robinswood            Robinswood Hill    TRUE

如果您想在 post 中显示输出,您可以在 res 上进一步玩一些技巧,例如,

res2 <- do.call(
  cbind,
  lapply(
    u <- with(subset(res, matched), split(Var1, Var2)),
    function(x) `length<-`(as.vector(x), max(lengths(u)))
  )
)

这样

> res2
     Cotswold Water Park Pit 28 Cotswold Water Park Pit 14 Robinswood Hill
[1,] "Pit 28"                   "Pit 28"                   "Robinswood"
[2,] "28"                       "CWP Pit 28"               NA
[3,] "CWP Pit 28"               "Cotswold 28"              NA
[4,] "Cotswold 28"              "14"                       NA

也许您正在寻找 adist:

x <- adist(messy, approved, fixed=FALSE, ignore.case = TRUE)
y <- t(adist(approved, messy, fixed=FALSE, ignore.case = TRUE))
i <- x == apply(x, 1, min)
y[!i]  <- NA
colnames(y) <- approved
i <- apply(y == apply(y, 1, min, na.rm=TRUE), 2, function(i) messy[i & !is.na(i)])
do.call(cbind, lapply(i, function(x) x[seq_len(max(lengths(i)))]))
#     Cotswold Water Park Pit 28 Cotswold Water Park Pit 14 Robinswood Hill
#[1,] "Pit 28"                   "14"                       "Robinswood"   
#[2,] "28"                       NA                         NA             
#[3,] "CWP Pit 28"               NA                         NA             
#[4,] "Cotswold 28"              NA                         NA             

基本 R 选项为:

result <- sapply(approved, function(x) grep(gsub('\s+', '|', x), messy, value = TRUE))
result
#$`Cotswold Water Park Pit 28`
#[1] "Pit 28"      "28"          "CWP Pit 28"  "Cotswold 28"

#$`Cotswold Water Park Pit 14`
#[1] "Pit 28"      "CWP Pit 28"  "Cotswold 28" "14"         

#$`Robinswood Hill`
#[1] "Robinswood"

这里的逻辑是我们在 approved 中的每个空格处插入竖线 (|) 符号,并且 return 在 messy 中的单词(如果任何单词匹配)。

要获得与所示格式相同的输出,我们可以这样做:

sapply(result, `[`, 1:max(lengths(result)))

#     Cotswold Water Park Pit 28 Cotswold Water Park Pit 14 Robinswood Hill
#[1,] "Pit 28"                   "Pit 28"                   "Robinswood"   
#[2,] "28"                       "CWP Pit 28"               NA             
#[3,] "CWP Pit 28"               "Cotswold 28"              NA             
#[4,] "Cotswold 28"              "14"                       NA   

这是一个高度灵活的 regex_join 解决方案

library( fuzzyjoin )
library( data.table )
#make data.frames
messy.df <- data.frame( messy ); approved.df <- data.frame( approved )
#create regexes
messy.df$regex <- gsub( " ", "|", messy.df$messy )
#regex join
ans <- regex_full_join( approved.df, messy.df, by = c("approved" = "regex") )
#cast to wide
dcast( setDT(ans), messy~approved, value.var = "messy")[, -1]

#      Cotswold Water Park Pit 14 Cotswold Water Park Pit 28 Robinswood Hill
#   1:                         14                       <NA>            <NA>
#   2:                       <NA>                         28            <NA>
#   3:                 CWP Pit 28                 CWP Pit 28            <NA>
#   4:                Cotswold 28                Cotswold 28            <NA>
#   5:                     Pit 28                     Pit 28            <NA>
#   6:                       <NA>                       <NA>      Robinswood

这是使用 stringi 的一种可能性(比 stringr 快,通常比基本 R 正则表达式操作快。这个解决方案 returns 一个列表应该比长度可变时的矩阵。

library(stringi)
messy_ors <- stri_replace_all(messy, " ", "|")  
lapply(approved, function(x) messy[stri_detect(x, regex = messy_ors)]) 

$`Cotswold Water Park Pit 28`
[1] "Pit 28"      "28"          "CWP Pit 28"  "Cotswold 28"

$`Cotswold Water Park Pit 14`
[1] "Pit 28"      "CWP Pit 28"  "Cotswold 28" "14"         

$`Robinswood Hill`
[1] "Robinswood"

如果你真的需要一个矩阵,你可以用类似的东西转换输出:

n <- max(lengths(out))
sapply(out, function(x) x[1:n])