ggplot2 multiline title, different indentations

Question

I am generating graphs for a publication and I\'d like to be able to label the panels of a figure in ggplot itself (as opposed to exporting to publisher, etc) so that they j

Answer 1

Update: Since ggplot2 3.0.0 there is now native support for plot labels, see this answer.

Here is how I would do it, using the cowplot package that I wrote specifically for this purpose. Note that you get a clean theme as a bonus.

library(cowplot)

p <- ggplot(iris, aes(x = Sepal.Length, y = Sepal.Width, color = Species, shape = Species)) +
  geom_jitter(size = 3.5) +
  ggtitle("The Actual Long, Normal Title of Titliness")

# add one label to one plot
ggdraw(p) + draw_plot_label("A")

# place multiple plots into a grid, with labels
plot_grid(p, p, p, p, labels = "AUTO")

You then want to use the save_plot function to save plots instead of ggsave, because save_plot has defaults and parameters that help you get the scaling right relative to the theme, in particular for plots in a grid.

Answer 2

The easiest way is probably to use a title and a subtitle,

ggplot(iris, aes(x = Sepal.Length, y = Sepal.Width, color = Species, shape = Species))+
  geom_jitter(size = 6.5) +
  labs(title = "A", subtitle = "The Actual Long, Normal Title of Titliness") +
  theme(plot.subtitle = element_text(hjust = 0.5))

Answer 3

You can use grid.text from package grid, add text to your plot. Firstly add some space above your title use plot.margin.

library(grid)
p <- ggplot(iris, aes(x = Sepal.Length, y = Sepal.Width, color = Species, shape = Species))+
geom_jitter(size = 6.5)+
ggtitle("The Actual Long, Normal Title of Titliness")+
theme(plot.title = element_text(hjust = 0,face = "bold", size = 30),
      axis.ticks = element_blank(),
      legend.text = element_text(size = 25),
      axis.title = element_text(size = 25, face = "bold"),
      axis.text = element_text(size = 25, vjust = 0.05),
      legend.position = "bottom", 
      plot.margin = unit(c(4, 3, 1, 1), "lines"))
p
grid.text('A', x = unit(0.1, 'npc'), y = unit(.90, 'npc'), gp = gpar(fontsize=28))

Answer 4

You can do this by manipulating Grobs. Using gtable and grid on top of ggplot2.

library("ggplot2")
library("gtable")
library("grid")

p <- ggplot(iris, aes(x = Sepal.Length, y = Sepal.Width, color = Species, shape = Species))+
  geom_jitter(size = 6.5)+
  ggtitle("The Actual Long, Normal Title of Titliness")+
  theme(plot.title = element_text(hjust = 0.5, face = "bold", size = 30),
        axis.ticks = element_blank(),
        legend.text = element_text(size = 25),
        axis.title = element_text(size = 25, face = "bold"),
        axis.text = element_text(size = 25, vjust = 0.05),
        legend.position = "bottom",
        plot.margin = unit(c(4, 1, 1, 4), "lines"))  # We need bigger top/left margins to show the letter

gt <- ggplot_gtable(ggplot_build(p))  # Building a gtable from the ggplot object
# Adding the textGrob for the panel letter
panel_letter = textGrob("A", x = 0.5, y = .9, 
                        just = c("left", "top"), 
                        gp = gpar(fontsize = 40, col =  "black", face="bold"))
gt <- gtable_add_grob(gt, panel_letter, t=1, l=1, r=1)  # Append the Grob to the table

p <- grid.draw(gt)  # Display the plot
ggsave("plot.png",gt, width=10, height=10)  # If you want to save it.

Answer 5

Since ggplot2 3.0.0, there is a native way to do this, using the tag label:

ggplot(iris, aes(x = Sepal.Length, y = Sepal.Width, color = Species, shape = Species)) +
  geom_point() +
  labs(title = "The Actual Long, Normal Title of Titliness",
       tag = "A")