Code for searching Twitter using the twitteR #rstats package.

iworkfortheinternet.R

require(plyr); require(stringr); require(ggplot2); require(lubridate); require(twitteR)

##need to figure out why there are two datout objects and not just 1...
twitterPlot<-function(myString, n=1500, since=NULL, until=NULL){ 

  since2<-as.character(strptime(since, '%Y-%m-%d')+2*24*60*60)
  until2<-as.character(strptime(until, '%Y-%m-%d')+2*24*60*60)

  datout_1 <- searchTwitter(myString, n = n, since=since, until=until)
  datout_2 <- searchTwitter(myString, n = n, since=since2, until=until2)
  datoutdf <- ldply(c(datout_1, datout_2), function(x) x$toDataFrame(), .progress="text")


  #what is input string 135 is invalid in this locale about 
  #and why is it causing scrip to fail?  happens with this grep...
  actual <- grep(myString, datoutdf[,1], ignore.case=T) 

  datoutdf2 <- datoutdf[actual,]

  datoutdf2$newtime <- round_date(datoutdf2[,4], "hour")
  datoutdf2_ <- ddply(datoutdf2, .(newtime), summarise,
	numtweets = length(newtime))

  ret<-ggplot(droplevels(datoutdf2_), aes(newtime, numtweets)) +
	theme_bw(base_size=18) +
	geom_line(color="red") +
	labs(x='\nTime', y='Number of tweets\n') +
	opts(title=paste("Tweets containing", myString, sep=" "))

  return(ret)
}

#make the ggplot2 object
working<-twitterPlot("I work for the internet", n = 1500, since='2011-11-11', until='2011-12-12')

#plot and save
working
ggsave("iworkfortheinternet.png")