Question

我正在尝试获取所有词干列表及其原始形式。

这是一个例子

library(tm)
text <- c("Very Impressed with the shipping time, it arrived a few days earlier than expected", "it was very helpful","It was a wonderful experience")
corpus<-Corpus(VectorSource(text))
corpus<-tm_map(corpus,stemDocument)

我在数据框中寻找这样的答案

 orginal_word   stemmed 
 Impressed      Impress 
 shipping        ship
 very            veri
 helpful         help
 wonderful       wonder
 experience      experi

Answer 1

这可能对您有所帮助。 wordStem()包中有一个名为SnowballC的函数。使用它，您可以执行以下操作。由于我在unnest_tokens()包中使用tidytext，因此我首先创建了一个数据框。该函数拆分单词并创建长格式数据集。您似乎想删除停用词，因此我使用了filter()。最后一步对你来说至关重要。我在wordStem()包中使用SnowballC来提取数据中剩余字词的词干。结果可能不完全是你想要的。但我希望这会在某种程度上帮助你。

library(dplyr)
library(tidytext)
library(SnowballC)

mydf <- data_frame(id = 1:length(text),
                   text = text)

data(stop_words)

mydf %>%
unnest_tokens(input = text, output = word) %>%
filter(!word %in% stop_words$word) %>%
mutate(stem = wordStem(word))

#      id       word    stem
#   <int>      <chr>   <chr>
# 1     1  impressed impress
# 2     1   shipping    ship
# 3     1       time    time
# 4     1    arrived   arriv
# 5     1       days     dai
# 6     1    earlier earlier
# 7     1   expected  expect
# 8     2    helpful    help
# 9     3  wonderful  wonder
#10     3 experience  experi

Answer 2

这比@ jazzurro的回答更有效：

library("corpus")
text <- c("Very Impressed with the shipping time, it arrived a few days earlier than expected", "it was very helpful","It was a wonderful experience")
word <- text_types(text, collapse = TRUE, drop = stopwords_en, drop_punct = TRUE)
stem <- SnowballC::wordStem(word, "english")
data.frame(word, stem)

结果：

         word    stem
1     arrived   arriv
2        days     day
3     earlier earlier
4    expected  expect
5  experience  experi
6     helpful    help
7   impressed impress
8    shipping    ship
9        time    time 
10  wonderful  wonder

（text_types函数也接受tm语料库对象，如果这对你很重要。）

如何在R中执行stemDocument的所有词干列表及其原始格式

2 个答案: