# 2005 年 06 月 15 日作成
# number of repeated sample
no.rep<-5000
# function of sampling median from population with sample size no.sample
sampling<-function(no.sample=5) rt(no.sample,2)
# calculation mean and median
sample.mean.and.median<-function(x)c(mean(x),median(x))
# defining objects to store results
res<-matrix(0,no.rep,2)
for (i in 1:no.rep) res[i,]<-sample.mean.and.median(sampling())
plot(density(res[,2]),col=1,xlim=c(-3,3),ylim=c(0,1.0),type="l",main="", 
xlab="sampling distribution of median for n = 5, 25, 100")
lines(density(res[,1]),col=2)