R/mypackagebin.R

In nafryer97/MATH4753PROJ1: Introductory Package

#' mybin
#'
#' Generates samples with a binomial distribution given number of samples, number of iterations,
#' and a probability
#'
#' @param iter number of samples to generate
#' @param n number of trials
#' @param p probability of success
#'
#' @return a table representing the observed number of successes
#'
#' @export
#'
#' @examples
#'
#' mybin(iter=100,n=10,p=0.7)
#' mybin(iter=200,n=10,p=0.7)
#' mybin(iter=500,n=10,p=0.7)
#' mybin(iter=1000,n=10,p=0.7)
#' mybin(iter=10000,n=10,p=0.7)
mybin=function(iter,n,p)
{
  # 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")
  succ.tab/iter
}