R删除data.table中的多个文本字符串

Question

我有一个 vector 单词要从 data.table DT 中删除，如下所示。

wordstoremove <- c("Simpson", "Flander", "Nahasapeemapetilon", "Spuckler", "Wiggum")

DT <- structure(list(vid = c("Simpsons", "Flanders", "Nahasapeemapetilons", 
                             "Spucklers", "Wiggums"), wr1 = c("Homer Simpson", "Ned Flanders", 
                                                              "Apu Nahasapeemapetilon", "Cletus Spuckler", "Chief Wiggum"), 
                     wr2 = c("Bart Simpson", "Rod Flanders", "Manjula Nahasapeemapetilon", 
                             "Brandine Spuckler", "Ralph Wiggum"), wr3 = c("Marge Simpson", 
                                                                           "Todd Flanders", "Sanjay Nahasapeemapetilon", NA, "Sarah Wiggum"
                             )), .Names = c("vid", "wr1", "wr2", "wr3"), row.names = c(NA, 
                                                                                       -5L), class = c("data.table", "data.frame"))

DT
                   vid                    wr2                        wr2                       wr3
1:            Simpsons          Homer Simpson               Bart Simpson             Marge Simpson
2:            Flanders           Ned Flanders               Rod Flanders             Todd Flanders
3: Nahasapeemapetilons Apu Nahasapeemapetilon Manjula Nahasapeemapetilon Sanjay Nahasapeemapetilon
4:           Spucklers        Cletus Spuckler          Brandine Spuckler                        NA
5:             Wiggums           Chief Wiggum               Ralph Wiggum              Sarah Wiggum

我知道我可以使用 R remove multiple text strings in data frame 中的解决方案.

如何使用 data.table 来最小化数据复制？

Answer 1

试试这个:

library(data.table)
foo <- function(x) gsub(paste0(wordstoremove, collapse="s?|"), "", x)
DT[, names(DT)[-1] := lapply(.SD, foo), .SDcols = names(DT)[-1]]
DT
#                    vid     wr1       wr2     wr3
# 1:            Simpsons  Homer      Bart   Marge 
# 2:            Flanders    Ned       Rod    Todd 
# 3: Nahasapeemapetilons    Apu   Manjula  Sanjay 
# 4:           Spucklers Cletus  Brandine       NA
# 5:             Wiggums  Chief     Ralph   Sarah