在尝试自学R时，我跟随以下示例：
https://www.r-bloggers.com/how-to-use-r-to-scrape-tweets-super-tuesday-2016/
在这个例子中，作者Kris Eberwein描述了以下功能：
score.sentiment = function(sentences, good_text, bad_text, .progress='none')
{
require(plyr)
require(stringr)
# we got a vector of sentences. plyr will handle a list
# or a vector as an "l" for us
# we want a simple array of scores back, so we use
# "l" + "a" + "ply" = "laply":
scores = laply(sentences, function(sentence, good_text, bad_text) {
# clean up sentences with R's regex-driven global substitute, gsub():
sentence = gsub('[[:punct:]]', '', sentence)
sentence = gsub('[[:cntrl:]]', '', sentence)
sentence = gsub('\d+', '', sentence)
#to remove emojis
sentence <- iconv(sentence, 'UTF-8', 'ASCII')
sentence = tolower(sentence)
# split into words. str_split is in the stringr package
word.list = str_split(sentence, '\s+')
# sometimes a list() is one level of hierarchy too much
words = unlist(word.list)
# compare our words to the dictionaries of positive & negative terms
pos.matches = match(words, good_text)
neg.matches = match(words, bad_text)
# match() returns the position of the matched term or NA
# we just want a TRUE/FALSE:
pos.matches = !is.na(pos.matches)
neg.matches = !is.na(neg.matches)
# and conveniently enough, TRUE/FALSE will be treated as 1/0 by sum():
score = sum(pos.matches) - sum(neg.matches)
return(score)
}, good_text, bad_text, .progress=.progress )
scores.df = data.frame(score=scores, text=sentences)
return(scores.df)
}
然而，当我运行此命令时，我收到以下错误：
> score.sentiment = function(sentences, good_text, bad_text, .progress='none')
+ {
+ require(plyr)
+ require(stringr)
+ # we got a vector of sentences. plyr will handle a list
+ # or a vector as an "l" for us
+ # we want a simple array of scores back, so we use
+ # "l" + "a" + "ply" = "laply":
+ scores = laply(sentences, function(sentence, good_text, bad_text) {
+
+ # clean up sentences with R's regex-driven global substitute, gsub():
+ sentence = gsub('[[:punct:]]', '', sentence)
+ sentence = gsub('[[:cntrl:]]', '', sentence)
+ sentence = gsub('\d+', '', sentence)
Error: '\d' is an unrecognized escape in character string starting "'\d"
> #to remove emojis
> sentence <- iconv(sentence, 'UTF-8', 'ASCII')
Error in iconv(sentence, "UTF-8", "ASCII") : object 'sentence' not found
> sentence = tolower(sentence)
Error in tolower(sentence) : object 'sentence' not found
> # split into words. str_split is in the stringr package
> word.list = str_split(sentence, '\s+')
Error: '\s' is an unrecognized escape in character string starting "'\s"
> # sometimes a list() is one level of hierarchy too much
> words = unlist(word.list)
Error in unlist(word.list) : object 'word.list' not found
>
> # compare our words to the dictionaries of positive & negative terms
> pos.matches = match(words, good_text)
> neg.matches = match(words, bad_text)
>
> # match() returns the position of the matched term or NA
> # we just want a TRUE/FALSE:
> pos.matches = !is.na(pos.matches)
> neg.matches = !is.na(neg.matches)
>
> # and conveniently enough, TRUE/FALSE will be treated as 1/0 by sum():
> score = sum(pos.matches) - sum(neg.matches)
>
> return(score)
Error: no function to return from, jumping to top level
> }, good_text, bad_text, .progress=.progress )
Error: unexpected '}' in " }"
>
> scores.df = data.frame(score=scores, text=sentences)
Error in data.frame(score = scores, text = sentences) :
object 'scores' not found
> return(scores.df)
Error: object 'scores.df' not found
> }
Error: unexpected '}' in "}"
由于此博客帖子的评论已经结束，我以为我会求助于SO。谁能解释我做错了什么;或者，至少，解释这些错误意味着什么？我在R的这个会话中加载了以下包：
library(twitteR)
library(ROAuth)
library(httr)
library(plyr)
library(stringr)
感谢您的帮助！