在 R 中将多个参数作为列表传递

Question

我希望将参数列表作为向量传递给 R 中的另一个命令。我不想每次都重复同一组参数。

这是我必须对范围 t1 to t6.

范围内的每个 $full_text 列数据帧运行 6 次的代码

    library(quanteda)

t1t <- tokens(t1$full_text, what = 'word', remove_numbers = TRUE,
                 remove_punct = TRUE,
                 remove_symbols = TRUE,
                 remove_separators = TRUE,
                 remove_twitter = TRUE,
                 remove_hyphens = TRUE,
                 remove_url = TRUE)
t1t <- tokens_tolower(t1t)
t1t <- tokens_select(t1t, stopwords(), selection = "remove")
t1t <- unlist(t1t)
t1t <- unique(t1t)
t1t <- as.data.frame(t1t)
t1t <- as.data.frame.matrix(t1t)

有没有办法传递一次性参数。

Answer 1

如错误消息中所述tokens 期望字符向量、语料库或标记作为输入。您正在将数据框传递给它。而是将相应的文本列传递给它。

tokens 还可以处理向量，因此您可以将多列作为一个向量一起传递。

library(quanteda)

tokens(c(t1$colname, t2$colname, t3$colname), what = "word", remove_numbers = TRUE, 
  remove_punct = TRUE, remove_symbols = TRUE, remove_separators = TRUE, 
  remove_twitter = TRUE, remove_hyphens  =TRUE, remove_url = TRUE)

基于 ?tokens

的更新并以帮助页面为例

t1 <- data.frame(full_text = "#textanalysis is MY <3 4U @myhandle gr8 #stuff :-)", 
              stringsAsFactors = FALSE)
t2 <- data.frame(full_text = c("This is  in 999 different ways,\n up and down; 
    left and right!", "@kenbenoit working: on #quanteda 2day\t4ever, 
    http://textasdata.com?page=123."), stringsAsFactors = FALSE)

我们可以创建一个函数将其应用于所有数据帧

 complete_function <- function(x) {
   t1t <- tokens(x, what = 'word', remove_numbers = TRUE,
                  remove_punct = TRUE,
                  remove_symbols = TRUE,
                  remove_separators = TRUE,
                  remove_twitter = TRUE,
                  remove_hyphens = TRUE,
                  remove_url = TRUE)
   t1t <- tokens_tolower(t1t)
   t1t <- tokens_select(t1t, stopwords(), selection = "remove")
   t1t <- unlist(t1t)
   t1t <- unique(t1t)
   t1t <- as.data.frame(t1t)
   t1t <- as.data.frame.matrix(t1t)
}

然后使用mget获取数据帧t1、t2、t3等并将该函数应用于每个数据帧的"full_text"列。

lapply(mget(ls(pattern = "^t\d+")), function(x) complete_function(x$full_text))

#$t1
#           t1t
#1 textanalysis
#2           4u
#3     myhandle
#4          gr8
#5        stuff

#$t2
#        t1t
#1 different
#2      ways
#3      left
#4     right
#5 kenbenoit
#6   working
#7  quanteda
#8      2day
#9     4ever

在 R 中将多个参数作为列表传递

Passing multiple arguments as a list in R

r

text-mining

quanteda