#  2004 年 12 月 14 日作成
# simulation of CLT from uniform sample
num.rep<-10000
# number of sample size
num.sample<-3
s<-rep(0,num.rep)
#
#
# generate sample mean
#
for (i in 1:num.sample){
  s<-s+runif(num.rep,0,1)/num.sample
}
# 
#
# drat graph of centered sample mean 
#
plot(density(sqrt(12*num.sample)*(s-1/2)),xlim=c(-4,4),ylim=c(0,0.5),type="l",xlab="",ylab="")
xx<-seq(-4,4,by=0.001)
par(new=T)
#
# drat graph of standard normal
#
plot(xx,dnorm(xx,0,1),xlim=c(-4,4),ylim=c(0,0.5),type="l",xlab="",ylab="")
num.sample<-7
s<-rep(0,num.rep)
for (i in 1:num.sample){
  s<-s+runif(num.rep,0,1)/num.sample
}
par(new=T)
# 
#
# drat graph of centered sample mean 
#
plot(density(sqrt(12*num.sample)*(s-1/2)),xlim=c(-4,4),ylim=c(0,0.5),type="l",xlab="",ylab="")