This post describes how to build an area chart using base R and the `polygon()`

function. See the area chart section for a `ggplot2`

implementation.

`ggplot2`

and `geom_line()`

Base R also allows to build area charts thanks to the `polygon()`

function. This functions requires 2 inputs: `x`

and `y`

.

Note that extreme values of both are added at the beginning and at the end of each vectors to make sure the polygon is closed.

```
# Create data
data <- data.frame(
x=seq(1,10),
y=sample(seq(1,15),10)
)
# Add line on top
plot( data$x , data$y , col=rgb(0.2,0.1,0.5,0.9) , type="o" , lwd=3 , xlab="" , ylab="size" , pch=20)
# Fill the area
polygon(
c(min(data$x), data$x , max(data$x)) ,
c( min(data$y) , data$y , min(data$y)) ,
col=rgb(0.2,0.1,0.5,0.2) , border=F
)
```