R plotting example: Box office performance and tweets

boxtweets.R

# Data came in a series of directories named for major movies, 
# each containing a variable number of files of corresponding tweets. 

# Function that determines the number of tweets for a movie, given the name of the directory where the files reside.
numtweets=function(moviedir){
  files=list.files(moviedir, full.names=TRUE)
  x={}
  howmany=0
  for (i in 1:length(files)){
    appending=readLines(files[i])
    howmany=howmany+length(appending)}
  return(howmany)
  }

# This was a class project, so I entered each movie by hand, as in this example:
Saw3D="/data/movies/Saw_3D/"
x[1]=numtweets(Saw3D)
# For a larger project, it would have made sense to do this automatically. 

# Data modification for plotting
money=as.numeric(gsub('[^0-9.]', '', data1$Opening.Box.Office.Performance))
names=as.character(data1$Name)

# Plotting
plot(money,x,xlim=c(5000000,(max(money)+5000000)),
    main="Correspondence between tweet counts and box office performance",
    xlab="Box office performance, in dollars", ylab="Number of tweets")
textxy(money,x,names)