Order the panels from right to left in ggplot

by Rtist   Last Updated January 04, 2018 08:26 AM

I have a data frame with 5 groups. I want to facet my data by group using ggplot. I need the panels to be ordered from right to left, and not from left to right (the default).

df <- data.frame(group=letters[1:5],
       x=1:5,
       y=1:5)
ggplot(df, aes(x,y)) + 
geom_point(size=3) + 
facet_wrap(~group)

By default the panels are ordered from left to right, so that group 'a' appears at the top-left of the graph. The panel at the bottom-right is empty (as there are only 5 groups). I want the panels to appear from right to left. That is, 'a' should appear at the top-right and the panel at the left-bottom should be empty. Any ideas?

Note: the question is not about the labels of the panels. It is also not about re-ordering the group with factor(). I looked at the facet_wrap() help, but the only options are the 'switch' and 'strip.position' arguments that deal with labels. The 'dir' argument allows vertical or horizontal position, which is not what I am looking for.

Thanks in advance

Tags : r ggplot2 facet


Answers 1


Here's a solution that's somewhat hacky, because it requires manual positioning. We create a plotting function and then plot the first row of plots (rows 1 to 3 of df and the second row of plots (rows 4 and 5 of df) separately. We lay them out using grid.arrange, but we add a blank grob (nullGrob()) in the second row to create the blank space. The manual adjustment of the widths argument is necessary to get the nullGrob() to take up just the right amount of space so that the plot line up vertically.

library(gridExtra)
library(grid)

pf = function(data, xrng, yrng) {
  ggplot(data, aes(x,y)) + 
    geom_point(size=3) + 
    facet_wrap(~ group) +
    scale_y_continuous(limits=yrng) +
    scale_x_continuous(limits=xrng)
}

grid.arrange(pf(df[1:3,], xrng=range(df$x), yrng=range(df$y)), 
             arrangeGrob(nullGrob(), pf(df[4:5,], xrng=range(df$x), yrng=range(df$y)), 
                         widths=c(1,2.22)), 
             ncol=1)

enter image description here

eipi10
eipi10
January 04, 2018 08:24 AM

Related Questions





Using ggplot2 to draw bar plot

Updated April 30, 2017 00:26 AM

Colors strips settings in faced-wrap ggplot

Updated May 20, 2017 13:26 PM