R adding word in the middle of grid arrange-CodePudding

I am writing R ggplot, and I am arranging multiple plots with grid.arrange.

Is there a way to add some words in in between two plots? I want the output to be like the red word.

Thank you for your help :)

library(ggplot2)
library(gridExtra)
P1 <- ggplot(mtcars, aes(x = mpg))  
  geom_histogram()
P2 <- ggplot(mtcars, aes(x = wt))  
  geom_histogram()
grid.arrange(P1, *I want to add some information here*,P2, ncol = 1, nrow = 2)

CodePudding user response：

You could use the grid.text function from grid library as follows

### Libraries
library(grid)
library(ggplot2)
library(gridExtra)

### Data
data(cars)

### Initiating plots
P1 <- ggplot(mtcars, aes(x = mpg))  
  geom_histogram()

P2 <- ggplot(mtcars, aes(x = wt))  
  geom_histogram()

### Display plots
grid.arrange(P1, P2, ncol = 1, nrow = 2) 
grid.text("I want to add some information here", 
          x=unit(0.25, "npc"), 
          y=unit(.52, "npc"),
          gp=gpar(fontsize=20, col="red"))

CodePudding user response：

One approach would be to create another ggplot with only text that you want and use it in cowplot::plot_grid

library(ggplot2)

P1 <- ggplot(mtcars, aes(x = mpg))   geom_histogram()

P2 <- ggplot()   
  annotate("text", x = 4, y = 25, size=8, 
           label = "This is some text in the middle", color = "red")   
  theme_void() 

P3 <- ggplot(mtcars, aes(x = wt))    geom_histogram()

cowplot::plot_grid(P1, P2, P3, rel_heights = c(1/2, 1/12, 1/2), 
                   align = "v", nrow = 3)