ggplot2 - Correctly arrange odd number of plots into one figure

Question

I have an odd number of plots to arrange into one figure and I desire to show the last plot centered in the last row of the figure.

Here some sample data:

Answer 1

You can use gridExtra::grid.arrange for this. All you need to do is specify the layout of the plots with a layout matrix.

library(ggplot2)
set.seed(99)

x_1 = data.frame(z = rnorm(100))
x_2 = data.frame(z = rnorm(100))
x_3 = data.frame(z = rnorm(100))

lst = list(x_1, x_2, x_3)

lst_p = list()

for (i in 1:length(lst)) {
lst_p[[i]] = ggplot(data=lst[[i]], aes(lst[[i]]$z)) + 
geom_histogram() +
xlab("X LAB") +
ylab("Y LAB") 
}

p_no_labels = lapply(lst_p, function(x) x + xlab("") + ylab(""))


#layout of plots

lay <- rbind(c(1,2),c(1,2),
              c(3,3))



#arrange the grid and specify the `layout_matrix`
gridExtra::grid.arrange(grobs=p_no_labels, layout_matrix=lay)