x = c("a", "b", "c", "d")
xx = sample(x, 1000, TRUE, prob =  c(0.15, 0.25, 0.40, 0.20))


xxt = table(xx)

#View(xxt)
pie(xxt)


y = c(1, 2, 3, 4)
yy = sample(y, 1000, TRUE, prob =  c(0.25, 0.15, 0.25, 0.35))
yyt = table(yy)

#View(yyt)
pie(yyt)

Z = rnorm(1000, 10, 2)
View(Z)
bk = (max(Z) - min(Z)) / 20
Z_e = seq(min(Z), to = max(Z), by = bk)
Z_e_T = table(cut(Z,19))
View(Z_e_T)

Z_hist = hist(Z, Z_e)