How to align a multiline title

Question

I have a problem with ggplot title positioning. When I use hjust argument to slide title a bit right, both lines undesirably slide left and right. I want them one under the other. drawlabel(),annototations are not useful for my case, because they depend on x and y axis and their units(date,currency,kg) which mean every time I have to adjust them. I want unique coordinate system, whatever I am plotting I can easily use same place for different plots.

An undesired example with code is shown below.

set.seed(10)
df <- data.frame(x=1:10,y=round(rnorm(10)*1:10,2))
ggplot(df,aes(x=x,y=y))+
 geom_line(size=0.75)+
 labs(title = 'Here comes my title like that some words\nand my second line title')+
 theme(
   plot.title.position = 'plot',
   plot.title = element_text(hjust = 0.075)
 )

Undesirable plot

Desirable plot

Answer 1

I agree with @stefan in the comments that there appears to be no way to do this with theme.

One hackish approach is to remove your hjust change and manually move the position of the title by editing the grid layout.

library(ggplot)
library(grid)
p <- ggplot(df,aes(x=x,y=y)) +
  geom_line(size=0.75) +
  labs(title = 'Here comes my title like that some words\nand my second line title') +
  theme(plot.title.position = 'plot')
grob <- ggplotGrob(p)
grob$layout[grob$layout$name == "title","l"] <- 4.5
grid.newpage()
grid.draw(grob)

You can change 4.5 as necessary for the desired effect.

Answer 2

ggtext provides tools that make it a bit easier to muck about with text. In the example below, using the <br> to add a newline we can then render this with the theme parameter element_textbox_simple (with a little padding around the text).

library(ggplot2)
library(ggtext)

set.seed(10)
df <- data.frame(x=1:10,y=round(rnorm(10)*1:10,2))

ggplot(df,aes(x=x,y=y))+
 geom_line(size=0.75)+
 labs(title = 'Here comes my title like that some words <br> and my second line title') +
 theme(
    plot.title.position = "plot",
    plot.title = element_textbox_simple(padding = margin(5.5, 5.5, 5.5, 5.5))
 )

Answer 3

I might miss the obvious, but a simple option is to use a subtitle :)

Now, the indentation with hjust with title and subtitle is also NOT the same, however, it seems to be a constant! Weirdly this is totally dependent on your device. For example, in my RStudio Viewer, I need a constant of ~2.1, for ggsave ~1.49, and with reprex, I need 1.525 (see the example). However, once found the constant, it is actually fairly consistent. At least - for me here.

Works also for negative hjust!

library(ggplot2)
set.seed(10)
df <- data.frame(x = 1:10, y = round(rnorm(10) * 1:10, 2))

p <- ggplot(df, aes(x, y)) +
  labs(
    title = "Here comes my title like that some words",
    subtitle = "and my second line title"
  )

hjusttitle <- 0.175

p +
  theme(
    plot.title = element_text(hjust = hjusttitle, size = 14),
    plot.subtitle = element_text(hjust = hjusttitle / 1.525, size = 14)
  )

hjusttitle <- -0.15

p +
  theme(
    plot.title = element_text(hjust = hjusttitle, size = 14),
    plot.subtitle = element_text(hjust = hjusttitle / 1.525, size = 14)
  )

hjusttitle <- 1

p +
  theme(
    plot.title = element_text(hjust = hjusttitle, size = 14),
    plot.subtitle = element_text(hjust = hjusttitle / 1.525, size = 14)
  )

^{Created on 2021-01-04 by the reprex package (v0.3.0)}