在R中绘制绘图外部图例

Question

我尝试使用xpd=TRUE将图例放在绘图之外，但图例一直在绘图内绘图。我该如何解决这个问题呢？

x = c(0,0,1,1,1)
y = c(0.4991,1.1423,1.2258,1.158,0.5148)
dat<-cbind(x,y)
point_shape = c(10,15,10,15,1)
dat<-data.frame(x,y,point_shape)

myTicks<-c(0,1)
plot(dat[,1],dat[,2], yaxt="n", xaxt="n", xlab="", ylab="",pch = dat$point_shape)
abline(0.4991,0.7267)
abline(1.1423,0.0157)
abline(0.4991,0.0157,lty=2)
axis(side = 1, at = myTicks)
axis(side = 2, at = myTicks)


legend("bottomleft", legend = c("apple", "orange", "tree"),
       bty = "n", xpd=FALSE, mar(c(7,7,7,7)), cex = 1, pch = c(10, 15, 1))

Answer 1

请参阅legend的帮助

也可以通过将x设置为列表中的单个关键字“bottom right”、"bottom“、”bottom left“、"left”、"topleft“、"top”、“top right”、"right“和”

“来指定位置。这会将图例放在绘图框架内的给定位置。

因此，您可以通过手动提供图例的坐标将图例放置在绘图区域之外：

legend(-0.2, 0.3, legend = c("apple", "orange", "tree"),
       bty = "n", xpd=TRUE, mar=c(7,7,7,7), cex = 1, pch = c(10, 15, 1))

Answer 2

使用inset并将xpd设置为true

legend("bottomleft", legend = c("apple", "orange", "tree"), inset=c(-0.15,0),
   bty = "n", xpd=TRUE, mar(c(7,7,7,7)), cex = 1, pch = c(10, 15, 1))