Error: argument is of length zero

[sabbyna]

I am currently doing sentiment analysis of twitter.
I cannot display the tweets and error says argument is of length zero. using shiny dashboard. what is wrong with this:

TABLE DATA

library(reshape)
sentimentAnalyser<-function(result)
{
#Creating a copy of result data frame
test1=result[[1]]
test2=result[[2]]
test3=result[[3]]

#Creating three different data frames for Score, Positive and Negative
#Removing text column from data frame

test1$text=NULL
test2$text=NULL
test3$text=NULL

#Storing the first row(Containing the sentiment scores) in variable q
osc=test1[1,]
psc=test2[1,]
nsc=test3[1,]
oosc=melt(osc, var="Score")
ppsc=melt(psc, var="Positive")
nnsc=melt(nsc, var="Negative") 
oosc["Score"] = NULL
ppsc["Positive"] = NULL
nnsc["Negative"] = NULL

#Creating data frame
table1 = data.frame(Text=result[[1]]$text, Score=oosc)
table2 = data.frame(Text=result[[2]]$text, Score=ppsc)
table3 = data.frame(Text=result[[3]]$text, Score=nnsc)

#Merging three data frames into one
final_table=data.frame(Text=table1$Text, Score=table1$value, Positive=table2$value, Negative=table3$value)
return(final_table)

}
percentage<-function(final_table)
{
#Positive Percentage

#Renaming
posSc=final_table$Positive
negSc=final_table$Negative

#Adding column
final_table$PosPercent = posSc/ (posSc+negSc)

#Replacing Nan with zero
pp = final_table$PosPercent
pp[is.nan(pp)] <- 0
final_table$PosPercent = pp*100

#Negative Percentage

#Adding column
final_table$NegPercent = negSc/ (posSc+negSc)

#Replacing Nan with zero
nn = final_table$NegPercent
nn[is.nan(nn)] <- 0
final_table$NegPercent = nn*100
#write.csv(table_final,file="SentiAnalysis.csv",append = FALSE)
return(final_table)

}
wordDatabase()

twtList<-reactive({twtList<-searchTwitter(input$celebrityname, n=input$maxTweets, lang="en") })
tweets<-reactive({tweets<-TweetFrame(twtList() )})

result<-reactive({result<-score.sentiment(tweets(), pos.words, neg.words, .progress='none')})

final_table<-reactive({final_table<-sentimentAnalyser( result() )})
table_final_percentage<-reactive({table_final_percentage<-percentage(final_table() )})

output$tabledata<-renderTable(table_final_percentage())