gistfile1.txt

#!/usr/bin/env Rscript

library(lubridate)
library(plyr)
library(ggplot2)

split.out <- function(string,split.at,position){
  sort(unlist(strsplit(string,split.at)))[[position]]
}

d <- ddply(read.csv('results.csv'), .(Identifiers), function(x){
  data.frame(
             date = ceiling_date(as.Date(
             (split.out
              (split.out
               (paste
                (unlist(x['Properties'])),
                '\\|',2),
               ':',1)), "%Y/%m/%d"),"year"),
             authors = length
               (unlist
                (strsplit
                 (paste(unlist(x['Description'])),', ')))
             )
})

p <- ggplot(d,aes(x=as.factor(date),y=authors))
p <- p + stat_boxplot()

png('author_vs_year.png')
print(p)