Left-adjust title in ggplot2, or absolute position for ggtitle

Question

I would like to left align the title in a plot like this

ggplot(data = economics, aes(x = date, y = unemploy)) +  geom_line() +  ggtitle("Unemployment in USA between 1967 and 2007") +  xlab("") +  ylab("Unemployed [thousands]") 

First attempt

ggplot(data = economics, aes(x = date, y = unemploy)) + geom_line() +  ggtitle("Unemployment in USA for some years") +  xlab("") +  ylab("Unemployed [thousands]") +  theme(plot.title = element_text(hjust = -0.45, vjust=2.12))) 

Yay success! But wait... there's more... now I want to change the title to something else.

ggplot(data = economics, aes(x = date, y = unemploy)) +  geom_line() +  ggtitle("Unemployment in USA between 1967 and 2007") +  xlab("") +  ylab("Unemployed [thousands]") +  theme(plot.title = element_text(hjust = -0.45, vjust=2.12)) 

So now I need to adjust hjust... :(

The question

How can I make the title left justified (a couple of pixels left of the y axis label or so) over and over again without messing with the hjust value? Or what is the relationship between hjust and the length of the string?

I have tried to annotate manually according to this question, but then I got only the title, and nothing else for some reason - and an error.

Thank you!

Answer 1

This question refers to this github tidyverse/ggplot2 solved issue: https://github.com/tidyverse/ggplot2/issues/3252

And it is implemented in ggplot2 (development version): https://github.com/tidyverse/ggplot2/blob/15263f7580d6b5100989f7c1da5d2f5255e480f9/NEWS.md

Themes have gained two new parameters, plot.title.position and plot.caption.position, that can be used to customize how plot title/subtitle and plot caption are positioned relative to the overall plot (@clauswilke, #3252).

To follow your example as a reprex:

# First install the development version from GitHub: #install.packages("devtools") #If required #devtools::install_github("tidyverse/ggplot2")  library(ggplot2) packageVersion("ggplot2") #> [1] '3.2.1.9000'  ggplot(data = economics, aes(x = date, y = unemploy)) +    geom_line() +   labs(x=NULL,        y="Unemployed [thousands]",        title = "Unemployment in USA for some years",        subtitle = "A subtitle possibly",        caption  = "NOTE: Maybe a caption too in italics.") +   theme(plot.caption = element_text(hjust = 0, face= "italic"), #Default is hjust=1         plot.title.position = "plot", #NEW parameter. Apply for subtitle too.         plot.caption.position =  "plot") #NEW parameter 

^{Created on 2019-09-04 by the reprex package (v0.3.0)}

Answer 2

Until someone comes up with a better solution, one way would be something like

library(ggplot2) library(grid) library(gridExtra) p <- ggplot(data = economics, aes(x = date, y = unemploy)) +     geom_line() +     labs(x = NULL, y = "Unemployed [thousands]", title = NULL)  title.grob <- textGrob(     label = "Unemployment in USA for some years",     x = unit(0, "lines"),      y = unit(0, "lines"),     hjust = 0, vjust = 0,     gp = gpar(fontsize = 16))  p1 <- arrangeGrob(p, top = title.grob) grid.draw(p1)