X = c("a","b","c","d")
prob = c(0.15,0.25,0.4,0.2)
XX = sample(x = X,size = 1000,replace = TRUE,prob = prob)

XXT = table(XX)


pdf(file = "XXP.pdf")
pie(XXT)
dev.off()

ytable = table(ysample)
barplot(ytable)
help(rnorm)

Z = rnorm(1000,mean = 10, sd = 2 )
help(seq)

Z_e = seq(min(Z)-0.1, max(Z)+1, 1)
Z_table = table(cut(Z,Z_e))
help(hist)
hist(Z,Z_e)