How to Change the Order of Facets in ggplot2 (With Example)


You can use the following basic syntax to specify the order of facets in ggplot2:

p +
  facet_grid(~factor(my_variable, levels=c('val1', 'val2', 'val3', ...)))

The following example shows how to use this syntax in practice.

Example: Change Order of Facets in ggplot2

Suppose we have the following data frame in R:

#create data frame
df <- data.frame(team=c('A', 'A', 'B', 'B', 'C', 'C', 'D', 'D'),
                 points=c(8, 14, 20, 22, 25, 29, 30, 31),
                 assists=c(10, 5, 5, 3, 8, 6, 9, 12))

#view data frame
df

  team points assists
1    A      8      10
2    A     14       5
3    B     20       5
4    B     22       3
5    C     25       8
6    C     29       6
7    D     30       9
8    D     31      12

The following code shows how to use facet_grid() to create a grid that displays a scatterplot of assists vs. points for each team:

library(ggplot2)

#create multiple scatter plots using facet_grid
ggplot(df, aes(assists, points)) +
  geom_point() +
  facet_grid(.~team)

By default, ggplot2 places the scatter plots in order based on which values appear first in the team variable in the data frame.

However, we can convert team to a factor variable and use the levels argument to specify the order that the teams should be placed in the plot:

library(ggplot2)

#create multiple scatter plots using facet_grid with specific order
ggplot(df, aes(assists, points)) +
  geom_point() +
  facet_grid(~factor(team, levels=c('C', 'D', 'A', 'B')))

change order of facets in ggplot2

Notice that the scatter plots are now in order based on the order we specified within the levels argument: C, D, A, B.

The advantage of using this approach is that we don’t actually modify the underlying data.

Instead, we only change the levels within the facet_grid() function.

Additional Resources

The following tutorials explain how to perform other common tasks in ggplot2:

How to Change Font Size in ggplot2
How to Remove a Legend in ggplot2
How to Rotate Axis Labels in ggplot2

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One Reply to “How to Change the Order of Facets in ggplot2 (With Example)”

  1. Contrary to what is written here, ggplot2 DOES NOT take the order of values appearing in the data. You can try this with the following data frame:
    df <- data.frame(team=c('D', 'D', 'B', 'B', 'C', 'C', 'A', 'A'),
    points=c(8, 14, 20, 22, 25, 29, 30, 31),
    assists=c(10, 5, 5, 3, 8, 6, 9, 12))

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