law*_*yeR 10 plot r underline ggplot2 plotmath
如果这是一个简单的问题,请原谅我的无知,但我似乎无法弄清楚如何强调情节标题的任何部分.我正在使用ggplot2.
我能找到的最好的是 手工制作的注释("段"),我创建了一个玩具图来说明它的方法.
df <- data.frame(x = 1:10, y = 1:10)
rngx <- 0.5 * range(df$x)[2] # store mid-point of plot based on x-axis value
rngy <- 0.5 * range(df$y)[2] # stores mid-point of y-axis for use in ggplot
ggplot(df, aes(x = x, y = y)) +
geom_point() +
ggtitle("Oh how I wish for ..." ) +
ggplot2::annotate("text", x = rngx, y = max(df$y) + 1, label = "underlining!", color = "red") +
# create underline:
ggplot2::annotate("segment", x = rngx-0.8, xend = rngx + 0.8, y= 10.1, yend=10.1)
Run Code Online (Sandbox Code Playgroud)

试试这个:
ggplot(df, aes(x = x, y = y)) + geom_point() +
ggtitle(expression(paste("Oh how I wish for ", underline(underlining))))
Run Code Online (Sandbox Code Playgroud)
或者,正如BondedDust在评论中指出的那样,您可以paste()完全避免通话,但要注意for:
ggplot(df, aes(x = x, y = y)) + geom_point() +
ggtitle(expression(Oh~how~I~wish~'for'~underline(underlining)))
Run Code Online (Sandbox Code Playgroud)
或巴蒂斯特提出了另一个,甚至更短的方法不使用expression,paste()或波浪线很多:
ggplot(df, aes(x = x, y = y)) + geom_point() +
ggtitle(~"Oh how I wish for "*underline(underlining))
Run Code Online (Sandbox Code Playgroud)