统计简单学_正态分布

#generate two data sets
#first normal, second from a t-distribution, third form a uniform-distribution
words1 = rnorm(100); words2 = rt(100,df=3);words3=runif(100)

#have a look at densities
plot(density(words1))
plot(density(words2))
plot(density(words3))


#perform the test
#hypothesis: normal distribution, it's rejected when p<0.05
shapiro.test(words1)
shapiro.test(words2)
shapiro.test(words3)


ks.test(x,"norm")

#plot using a qqplot
qqnorm(words1);qqline(words1,col=2)
qqnorm(words2);qqline(words2,col=2)
qqnorm(words3);qqline(words3,col=3)