如何仅在R基础图中将一个图例名称改为斜体？(How to only make one legend name italic in base R plot?)

如何仅在R基础图中将一个图例名称改为斜体？(How to only make one legend name italic in base R plot?)

我想添加一个图例，其中只有一个图例名称被斜体显示 。 我在base R中使用plot() 。

但是，我需要斜体行来包含可变数字，所以我使用bquote 。

我尝试过的东西不起作用：

a <- 2 ; b <- 5 plot(a,b) l1 <- bquote(Italic ~ .(a) + .(b)) l2 <- bquote(a + b) legend(x='topright',legend = bquote(italic(.(l1)))) legend(x='topleft',legend = c(bquote(italic(.(l1))),l2)) 请注意，当我自己离开表达式（右图）时，它会正确表示斜体。 但是，当我为其他图例行添加文本时，它会混淆（LEFT LEGEND）。

我该如何正确地做到这一点？

注意：我宁愿有一个不需要多次调用legend()的解决方案。

I want to add a legend to a plot in which only one of the legend names is italicized. I'm using plot() in base R.

However, I need that italicized line to contain variable numbers, so I use bquote.

What I've tried does not work:

a <- 2 ; b <- 5 plot(a,b) l1 <- bquote(Italic ~ .(a) + .(b)) l2 <- bquote(a + b) legend(x='topright',legend = bquote(italic(.(l1)))) legend(x='topleft',legend = c(bquote(italic(.(l1))),l2)) Notice that when I leave the expression on its own (RIGHT LEGEND), it italicizes correctly. However, when I add the text for other legend lines, it messes up (LEFT LEGEND).

How do I properly do this?

Note: I'd rather have a solution that doesn't require multiple calls to legend().

最满意答案

你可以使用text.font = 3 ，说：

legend(x='topleft',legend = c(bquote((.(l1))),l2), text.font=c(3,1))

You could use text.font = 3, say:

legend(x='topleft',legend = c(bquote((.(l1))),l2), text.font=c(3,1))