R/myHyper.R

In cbain1/MATH4753BAIN:

#' @title A Function to Mimic a Hypergeometric Distribution
#'
#' @param iter the number of iterations you want to run
#' @param N the number of total items in your population
#' @param r the number of success items in your population
#' @param n the number of items you wish to select from the population
#'
#' @return
#' @export
#'
myHyper=function(iter=100,N=20,r=12,n=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 over the trials
	succ=c()
	for( i in 1:iter){
		#Fill each column with a new sample
		sam.mat[,i]=sample(rep(c(1,0),c(r,N-r)),n,replace=FALSE)
		#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="HYPERGEOMETRIC simulation", xlab="Number of successes")
	succ.tab/iter
}