ggplot2:如何绘制包含特殊字符的列？

Question

我想为数据框创建一个图,其列名包含特殊字符.请考虑以下示例:

f <- data.frame(foo=c(1, 2, 3), bar=c(4, 5, 6))
# The following line works fine
ggplot(f) + geom_point(aes_string(x="foo", y="bar"))
names(f) <- c("foo", "bar->baz")
# The following also works, but seems not elegant
ggplot(f) + geom_line(aes(x=foo, y=f[,"bar->baz"])) 
# I'd like something like the following, but this doesn't work.
ggplot(f) + geom_line(aes_string(x="foo", y="bar->baz"))

最后一个命令的输出是:

Error in eval(expr, envir, enclos) : object 'bar' not found

有人知道创建这个情节的方法吗？或者这仅仅是ggplot的限制？

Answer 1

你应该添加反引号``像这样:

ggplot(f) + geom_line(aes_string(x="foo", y="`bar->baz`"))

要么

ggplot(f) + geom_line(aes(x=foo, y=`bar->baz`))