Object of type 'closure' is not subsettable - R - json

Question

I am using R to extract tweets and analyse their sentiment, however when I get to the lines below I get an error saying "Object of type 'closure' is not subsettable"
scores$drink = factor(rep(c("east"), nd))
scores$very.pos = as.numeric(scores$score >= 2)
scores$very.neg = as.numeric(scores$score <= -2)
Full code pasted below
load("twitCred.Rdata")
east_tweets <- filterStream("tweetselnd.json", locations = c(-0.10444, 51.408699, 0.33403, 51.64661),timeout = 120, oauth = twitCred)
tweets.df <- parseTweets("tweetselnd.json", verbose = FALSE)
##function score.sentiment
score.sentiment = function(sentences, pos.words, neg.words, .progress='none')
{
# Parameters
# sentences: vector of text to score
# pos.words: vector of words of postive sentiment
# neg.words: vector of words of negative sentiment
# .progress: passed to laply() to control of progress bar
scores = laply(sentences,
function(sentence, pos.words, neg.words)
{
# remove punctuation
sentence = gsub("[[:punct:]]", "", sentence)
# remove control characters
sentence = gsub("[[:cntrl:]]", "", sentence)
# remove digits?
sentence = gsub('\\d+', '', sentence)
# define error handling function when trying tolower
tryTolower = function(x)
{
# create missing value
y = NA
# tryCatch error
try_error = tryCatch(tolower(x), error=function(e) e)
# if not an error
if (!inherits(try_error, "error"))
y = tolower(x)
# result
return(y)
}
# use tryTolower with sapply
sentence = sapply(sentence, tryTolower)
# split sentence into words with str_split (stringr package)
word.list = str_split(sentence, "\\s+")
words = unlist(word.list)
# compare words to the dictionaries of positive & negative terms
pos.matches = match(words, pos.words)
neg.matches = match(words, neg.words)
# get the position of the matched term or NA
# we just want a TRUE/FALSE
pos.matches = !is.na(pos.matches)
neg.matches = !is.na(neg.matches)
# final score
score = sum(pos.matches) - sum(neg.matches)
return(score)
}, pos.words, neg.words, .progress=.progress )
# data frame with scores for each sentence
scores.df = data.frame(text=sentences, score=scores)
return(scores.df)
}
pos = readLines(file.choose())
neg = readLines(file.choose())
east_text = sapply(east_tweets, function(x) x$getText())
scores = score.sentiment(tweetseldn.json, pos, neg, .progress='text')
scores()$drink = factor(rep(c("east"), nd))
scores()$very.pos = as.numeric(scores()$score >= 2)
scores$very.neg = as.numeric(scores$score <= -2)
# how many very positives and very negatives
numpos = sum(scores$very.pos)
numneg = sum(scores$very.neg)
# global score
global_score = round( 100 * numpos / (numpos + numneg) )
If anyone could help with as to why I'm getting this error it will be much appreciated. Also I've seen other answeres about adding '()' when referring to the variable 'scores' such as scores()$.... but it hasn't worked for me. Thank you.

Answer 1

The changes below got rid of the error:
x <- scores
x$drink = factor(rep(c("east"), nd))
x$very.pos = as.numeric(x$score >= 2)
x$very.neg = as.numeric(x$score <= -2)