将单词排序为字母列表R.

Question

我有一个包含unigrams及其频率的数据框。我想以有效的方式按字母顺序分割单词的向量。我知道可以使用grep

完成此操作

uniPhrase<-unigramDF$phrase[order(unigramDF$phrase)]
as<-uniPhrase[grep(pattern = "^a", x = uniPhrase)]
bs<-uniPhrase[grep(pattern = "^b", x = uniPhrase)]
zs<-uniPhrase[grep(pattern = "^z", x = uniPhrase)]

但有没有办法用sapply来做？

Answer 1

尝试

lst <- setNames(lapply(paste0("^", letters), 
           function(x) uniPhrase[grep(x, uniPhrase)]), paste0(letters, 's'))

或者

lst2 <- split(uniPhrase, substr(uniPhrase, 1, 1))

names(lst2) <- names(lst)
identical(lst2, lst)
#[1] TRUE

数据

set.seed(48)
uniPhrase <- sample(paste0(letters, rep(paste0('word', 1:10), each=26)), 
         100, replace=TRUE)