使用tidyverse将一个字符向量的元素与另一个字符向量进行比较的更好的解决方案？

Question

你好！我的目标是比较两个字符向量-主要是同义词和另一个混合名。 mixnames中的字符串元素与同义词中的字符串元素不完全匹配，因此需要进行一些字符串比较。我的目标是从同义词中提取元素，这些元素看起来像混合名称中的内容。我尝试仅使用tidyverse来执行此操作，但失败了。我找到了一个使用base的解决方案。我知道有更好的方法，但是我无法解决。...

library(tidyverse)
#> Warning: package 'ggplot2' was built under R version 3.6.1
#> Warning: package 'tidyr' was built under R version 3.6.1
#> Warning: package 'dplyr' was built under R version 3.6.1

#Acetometaphin 

synonyms <- c("Pediatrix","Percocet-5","Percocet-Demi","Perdolan Mono","Perfalgan", 
              "Phenaphen","Phenaphen W/Codeine","Phenipirin","Phogoglandin","Pinex", 
              "Piramin","Pirinasol","Plicet","Polmofen","Predimol","Predualito",
              "Prodol","Prontina","Puernol","Pulmofen", "Pyregesic-C")

mixNames <- c("Liquiprin","Midol Maximum Strength","Midol PM Night Time Formula",
              "Midol Regular Strength" ,"Midol Teen Formula","Naldegesic",
              "Ornex Severe Cold Formula","Percocet","Percogesic with Codeine",
              "Propacet" )

尝试失败：

#####STUFF THAT DIDNT WORK!!!!

# cross2(
#   .x = synonyms, .y = mixNames  #lists - each list has 2 lists - each of those is an atomic vector of 1
# ) %>% 
#   map_dfc(lift(str_detect)) #lift - modifies function to take a list of arguments - works for nested lists 

#this returns a df just like the apply 

# mix_syn_lgl_df <- map_dfc(
#   mixNames,
#   ~ map_lgl(synonyms, str_detect, pattern = .x)
# )

# colnames(mix_syn_lgl_df) <- mixNames
# 
# mix_syn_lgl_df$synonyms <- synonyms

这实际上有效：

#remove mixture names from synonyms

mix_syn_lgl_mat <- sapply(mixNames, function(x){
  str_detect(string = synonyms, pattern = x)
}) #returns a matrix 21x10 of logicals while preserving colnames

rownames(mix_syn_lgl_mat) <- synonyms #add synoyms as rownames
#create a new object with a new col of sum of TRUES in row
mix_syn_lgl_mat2 <- cbind(mix_syn_lgl_mat, rowSums(mix_syn_lgl_mat)) 
#take the numerical matrix mix_syn_lgl_mat2 and return the row names where the last col (rowsums) > 0
badNames <- row.names(mix_syn_lgl_mat2[mix_syn_lgl_mat2[, ncol(mix_syn_lgl_mat2)] > 0, ])
#filter out those names from the synonyms vector
pureSyn <- synonyms[!(synonyms %in% badNames)]

^{由reprex package（v0.3.0）在2019-10-29创建}

Answer 1

[您似乎想要synonyms矢量，而没有与mixNames重叠的值。您可以子集synonyms删除匹配项。在此str_c / paste折叠mixNames，以创建具有所有mixNames的图案。然后，您只需要使用部分字符串匹配（即从那里开始的str_detect和grepl）。

这里使用stringr-有点整洁

synonyms[str_detect(synonyms, str_c(mixNames, collapse = "|"), negate = T)]

或使用基数R中的功能：

synonyms[!grepl(paste(mixNames, collapse = "|"), synonyms)]
# OR
grep(paste(mixNames, collapse = "|"), synonyms, value = T, invert = T)

作为站点说明，如果您想查看匹配字符串的替代方法，请查看stringdist或其他字符串距离函数/包。

Answer 2

我喜欢为这样的东西构建一个%g%运算符。以下内容将创建一个小标题，其中包含来自实际上有效：

的代码中的值

library(tidyverse)

`%g%` <- function(x, y) {
  z <- paste0(y, collapse = "|")
  grepl(z, x, ignore.case = T)
}

tibble(syn = synonyms) %>% 
  filter(!syn %g% mixNames)
#> # A tibble: 19 x 1
#>    syn                
#>    <chr>              
#>  1 Pediatrix          
#>  2 Perdolan Mono      
#>  3 Perfalgan          
#>  4 Phenaphen          
#>  5 Phenaphen W/Codeine
#>  6 Phenipirin         
#>  7 Phogoglandin       
#>  8 Pinex              
#>  9 Piramin            
#> 10 Pirinasol          
#> 11 Plicet             
#> 12 Polmofen           
#> 13 Predimol           
#> 14 Predualito         
#> 15 Prodol             
#> 16 Prontina           
#> 17 Puernol            
#> 18 Pulmofen           
#> 19 Pyregesic-C

类似地，仅获得mixNames中与synonym中的值匹配的药物：

tibble(syn = synonyms) %>% 
  filter(syn %g% mixNames)
#> # A tibble: 2 x 1
#>   syn          
#>   <chr>        
#> 1 Percocet-5   
#> 2 Percocet-Demi

^{由reprex package（v0.3.0）在2019-10-29创建}