Facets

In data visualization, we sometimes have the need to compare different groups, looking at data alongside each other. One method for doing this is creating a subplot for each group. These kinds of plots are known as Trellis displays. In ggplot2, they're called facets. Facets divide the data by some discrete or categorical variable and display the same type of graph for each data subset.

Let's look at electricity consumption versus GDP for different countries, which we calculated in the previous activity.

We don't know which country has the highest GDP or electricity consumption. Let's split the data now.

Using Facets to Split Data

In this section, we'll plot subsets of data as separate subplots. Let's begin by implementing the following steps:

1. Use the gapminder.csv dataset.
2. Make a scatter plot of Electricity_consumption_per_capita versus gdp_per_capita:

p <- ggplot (df, aes (x=gdp_per_capita, y=Electricity_consumption_per_capita)) + geom_point ()

3. Use facet_grid() to specify the variables...