With code I plot a combined figure:

library(ggplot2)
library(tidyverse)
library(patchwork)
library(glue)
library(cowplot)

small <- mtcars %>% 
  filter(carb %in% c(1, 2))

p1 <- qplot(mpg, wt, data = small, colour = cyl)
p2 <- qplot(mpg, data = small)   ggtitle("small")
p <- p1 | p2

n1 = 3
s1 = 'Zinc, Nickel, Silver'
n2 = 2
s2 = 'Copper, Aluminum'

text <- glue("The top {n1} commodities that price rose most are: {s1}; \\
    the top {n2} commodities that fell most are: {s2}.")
title <- ggdraw()   
  draw_label(text, size=12)

plot_grid(title, p, ncol=1, rel_heights=c(0.1, 1))

Out:

Now the problem is explanation text on the top could not adaptively start a newline to show all the content? Let's say if text is a long paragraph, it will exceed out of plot bound.

How could I solve this issue? Thanks for your comments and helps at advance.

CodePudding user response：

1. Imprecise but simple option. This just wraps based on count of characters, regardless of font size, specific letter widths, etc.

   text <- stringr::str_wrap(glue("The top {n1} commodities that price rose most are: {s1}; \\
                       the top {n2} commodities that fell most are: {s2}."), 80)
   

2. More control option. This uses ggtext::geom_textbox to define a textbox with specific width, reflecting font and specific characters. Could also include further options if you want to color or bold certain text within the title.

   ggplot()  
      ggtext::geom_textbox(data = tibble(label = text), 
                          width = unit(5, "inch"), box.colour = NA,
                          aes(label = label, x = 1, y = 1))  
     theme_void() -> t
   
   t / p   plot_layout(heights = c(1,5))