Introduction
Visualize your data - pie charts
11. Draw the pie chart
Check yourself

## Instruction

Now you know everything necessary to plot a pie chart, so let's do that.

First, we will add the polar coordinate system to our plot. We do this by adding the following command to ggplot:

coord_polar(theta = "y")

Setting this coordinate system changes how R interprets some of the other commands. The whole syntax will look like this:

ggplot(data = dataset, aes(x = "", y = numerical_variable, fill = categorical_variable)) + coord_polar(theta = "y") + geom_col(width = 1)

First, look at the second part of this code; we set the polar coordinates. Next, look at the mapping arguments in aes(). Here, we remove the x argument by setting it to "". We also set the y argument as the dataset's numerical variable and the fill argument as the dataset's categorical variable. Lastly we added geom_col(width = 1). In the polar coordinate system, this will plot wedges for each category. (When we use the familiar Cartesian system, which has two perpendicular axes, this command sets the bar size.)

## Exercise

Let's plot our data on a pie chart.

To do that, use the above syntax for the ggplot() function. Set france_beverages as the dataset, the percent column as y and the beverage column as fill. Pass this command to the object pie.

### Stuck? Here's a hint!

You should write:

pie <- ggplot(data = france_beverages, aes(x = "", y = percent, fill = beverage)) +
coord_polar(theta = "y") +
geom_col(width = 1)