R/bino.gen.R

In alanarnholt/PASWR: Probability and Statistics with R

#' Simulating Binomial Distribution
#' 
#' Function that generates and displays \emph{m} repeated samples of \emph{n}
#' Bernoulli trials with a given probability of success.
#' 
#' 
#' @param samples number of repeated samples to generate
#' @param n number of Bernoulli trials
#' @param pi probability of success for Bernoulli trial
#' @return \item{simulated.distribution}{Simulated binomial distribution}
#' \item{theoretical.distribution}{Theoretical binomial distribution}
#' @author Alan T. Arnholt
#' @keywords distribution
#' @examples
#' 
#' bino.gen(1000, 20, 0.75)
#' 
#' @export bino.gen
bino.gen <-
function(samples, n, pi) {
  values <- sample(c(0,1), samples*n, replace=TRUE, prob=c(pi,1-pi))
  value.mat <- matrix(values, ncol=n)
  Successes <- apply(value.mat, 1, sum)
  a1 <- round((table(Successes)/samples), 3)
  b1 <- round(dbinom(0:n, n, 1-pi), 3)
  names(b1) <- 0:n
  hist(Successes, breaks=c((-.5+0):(n+.5)), probability=TRUE,ylab="", main=" Theoretical Values Superimposed \n Over Histogram of Simulated Values", col=13)
  x <- 0:n
  fx <- dbinom(x, n, 1-pi)
  lines(x, fx, type="h")
  lines(x, fx, type="p", pch=16)
  list(simulated.distribution=a1, theoretical.distribution=b1)}