Simulating Random Cylinders

r <- sample(1:10, size = 50000, replace = T)
h <- sample(1:10, size = 50000, replace = T)
v <- pi * r^2 * h
df <- data.frame(r, h, v)

library(ggplot2)
library(dplyr)

df2 <- count(df, r, h)
ggplot(df2, aes(x=r, y=h, fill=n)) +
  geom_tile()

ggplot(df, aes(x = r)) + geom_bar()

ggplot(df, aes(x = h)) + geom_bar()

ggplot(df, aes(x = v)) + geom_histogram()

mean(v)

## [1] 666.1983