five.thirty.free

53free.r

library(plyr)
library(ggplot2)
library(grid)


election.data <- read.csv("http://www.oberlin.edu/faculty/cdesante/assets/downloads/election2012.csv")
five.thirty.free <- function (SIMS) {

  Mode <- function(X) {

    XX <- table(as.vector(X))
    names(XX)[XX == max(XX)]

  }

Electoral.Votes <- c()
  for ( i in 1:SIMS)  {
    Election.Draw <- ddply(election.data,
                           .(STATE, OBAMA, ERROR), summarise,
                           P = rnorm(1, OBAMA, ERROR/1.96)
    )

    Election.Draw$Win <-  ifelse(Election.Draw$P > 50 , 1, 0)
    Electoral.Votes[i] <- sum(Election.Draw$Win * election.data$COLLEGE)
  }

  Winner <- ifelse(Electoral.Votes>=270, "Obama", "Romney")
  P.Obama <- ifelse(Electoral.Votes>=270, 1, 0)
  mean(P.Obama)
  table(Winner)
  Title.Text <- bquote("Probability that Obama Wins the Election:" * " " * .(round(mean(P.Obama), 3)))
  Fill.Title <- c("Projected Winner: \n")
  X.Title <-  bquote("\n \n Electoral College Votes for Obama in" * " " * .(SIMS) * " " * "Simulations")
  Plot1 <- qplot(Electoral.Votes, geom="histogram", binwidth=.5, fill=factor(Winner), alpha=mean(as.numeric(Mode(Electoral.Votes)))) + theme_bw()  + scale_fill_manual(values=c("dodgerblue4", "red"))
  Plot2 <- Plot1    + labs(fill = Fill.Title , title = Title.Text, alpha="Mode of Obama's \n Electoral Votes: \n") + xlab(X.Title)  + ylab("Count \n")
  Plot3 <- Plot2  + guides(alpha = guide_legend("Mode of Obama's \n Electoral Votes: \n",
                                                override.aes = list(alpha = 0,
                                                                    colour = "white"),
                                                keywidth = unit(0, "cm")))
  Plot3 <- Plot3 + scale_y_continuous(expand = c(0, 0))
  Plot3
}

#Just specify the number of simulations you want to run:

five.thirty.free(2500)