A histogram can be created in R with the `hist`

function. By default a frequency histogram will be created, but you can create a density histogram setting `prob = TRUE`

. A box plot can be created with the `boxplot`

function.

```
# Sample data
set.seed(5)
x <- rnorm(400)
# Histogram
hist(x, prob = TRUE)
```

Sometimes it is interesting to overlay a box plot over a histogram. For that purpose you will need to use `par(new = TRUE)`

to add a plot over the previous, removing the axes of the box plot with `axes = FALSE`

, setting it horizontal with `horizontal = TRUE`

and using a color with transparency making use of `rgb`

to avoid hiding the histogram.

**Box plot over an histogram**

```
# Histogram
hist(x, prob = TRUE,
col = "white",
main = "")
# Add new plot
par(new = TRUE)
# Box plot
boxplot(x, horizontal = TRUE, axes = FALSE,
col = rgb(0, 0.8, 1, alpha = 0.5))
# Box around the plots
box()
```

See also