R/mybin.R

In calwatson40/wats0079MATH4753: Compilation of MATH4753 functions

#' Sampling Binomial Experiment
#'
#' @param iter number of iterations
#' @param n sample size
#' @param p probability of success
#'
#' @return barplot of successes in each sample
#' @importFrom graphics barplot
#' @importFrom grDevices rainbow
#' @export
#'
#' @examples
#' mybin(iter=100,n=10,p=0.7)
mybin=function(iter=100,n=10,p=0.5){

  #make a matrix to hold the samples
  #initially filled with NA's
  sam.mat=matrix(NA,nrow=n,ncol=iter,byrow=TRUE)

  #Make a vector to hold the number of successes in each trial
  succ=c()

  for(i in 1:iter){

    #Fill each column with a new sample
    sam.mat[,i]=sample(c(1,0),n,replace=TRUE, prob=c(p,1-p))

    #Calculate a statistic from the sample (this case it is the sum)
    succ[i]=sum(sam.mat[,i])
  }

  #Make a table of successes
  succ.tab=table(factor(succ,levels=0:n))

  #Make a barplot of the proportions
  barplot(succ.tab/(iter),col=rainbow(n+1),main="Binomial simulation",xlab="Number of successes",ylab="Relative frequency")
  succ.tab/iter
}