R：ggplot2，我可以将绘图标题设置为环绕并缩小文本以适合绘图吗？

Question

library(ggplot2)

my_title = "This is a really long title of a plot that I want to nicely wrap \n and fit onto the plot without having to manually add the backslash n, but at the moment it does not"

r <- ggplot(data = cars, aes(x = speed, y = dist))
r + geom_smooth() + #(left) 
opts(title = my_title)

我可以设置绘图标题以包围并缩小文本以适应情节吗？

Answer 1

我不认为ggplot2中有文本换行选项（我总是只是手动插入\ n）。但是，您可以通过以下方式更改代码来缩小标题文本的大小：

title.size<-10
r + geom_smooth() + opts(title = my_title,plot.title=theme_text(size=title.size))

事实上，你使用theme_text函数的文本的所有方面。

Answer 2

你必须手动选择要包装的字符数，但strwrap和paste的组合将做你想要的。

wrapper <- function(x, ...) 
{
  paste(strwrap(x, ...), collapse = "\n")
}

my_title <- "This is a really long title of a plot that I want to nicely wrap and fit onto the plot without having to manually add the backslash n, but at the moment it does not"
r + 
  geom_smooth() + 
  ggtitle(wrapper(my_title, width = 20))