r - ggplot2:轴上的花括号？

Question

在 answering a recent visualization问题我真的需要大括号来显示轴上的跨度，但我不知道如何在 ggplot2 中做到这一点。这是情节:



而不是刻度线，我真的希望 y 轴标签“双字母名称的第二个字母”有一个从 1 到 10(红色和蓝色第二个字母的垂直跨度)延伸的大括号。但我不确定如何做到这一点。 x 轴可以从类似的处理中受益。

代码在链接的 CrossValidated 问题中可用(并且对于这个示例来说不必要地复杂，所以我不会展示它)。相反，这是一个最小的例子:

library(ggplot2)
x <- c(runif(10),runif(10)+2)
y <- c(runif(10),runif(10)+2)
qplot(x=x,y=y) +
  scale_x_continuous("",breaks=c(.5,2.5),labels=c("Low types","High types") )

在这种情况下，从 (0,1) 为低类型和从 (2,3) 为高类型的大括号将是理想的，而不是刻度线。

我宁愿不使用 geom_rect因为:

刻度线将保留

我更喜欢牙套

它将在情节内部而不是外部

我将如何做到这一点？完美的答案应该是:

漂亮、光滑、纤细的花括号

绘制在绘图区之外

通过高级参数指定(理想情况下是传递给 breaks 中的 scale_x_continuous 选项的范围类型对象)

Answer 1

使用绘制大括号的函数的另一种解决方案。

谢谢古尔!

curly <- function(N = 100, Tilt = 1, Long = 2, scale = 0.1, xcent = 0.5,
                  ycent = 0.5, theta = 0, col = 1, lwd = 1, grid = FALSE){

# N determines how many points in each curve
# Tilt is the ratio between the axis in the ellipse 
#  defining the curliness of each curve
# Long is the length of the straight line in the curly brackets 
#  in units of the projection of the curly brackets in this dimension
# 2*scale is the absolute size of the projection of the curly brackets 
#  in the y dimension (when theta=0)
# xcent is the location center of the x axis of the curly brackets
# ycent is the location center of the y axis of the curly brackets
# theta is the angle (in radians) of the curly brackets orientation
# col and lwd are passed to points/grid.lines

           ymin <- scale / Tilt
           y2 <- ymin * Long
           i <- seq(0, pi/2, length.out = N)

           x <- c(ymin * Tilt * (sin(i)-1),
                  seq(0,0, length.out = 2),
                  ymin * (Tilt * (1 - sin(rev(i)))),
                  ymin * (Tilt * (1 - sin(i))),
                  seq(0,0, length.out = 2),
                  ymin * Tilt * (sin(rev(i)) - 1))

           y <- c(-cos(i) * ymin,
                  c(0,y2),
                  y2 + (cos(rev(i))) * ymin,
                  y2 + (2 - cos(i)) * ymin,
                  c(y2 + 2 * ymin, 2 * y2 + 2 * ymin),
                  2 * y2 + 2 * ymin + cos(rev(i)) * ymin)

           x <- x + xcent
           y <- y + ycent - ymin - y2

           x1 <- cos(theta) * (x - xcent) - sin(theta) * (y - ycent) + xcent
           y1 <- cos(theta) * (y - ycent) + sin(theta) * (x - xcent) + ycent

           ##For grid library:
           if(grid){
              grid.lines(unit(x1,"npc"), unit(y1,"npc"),gp=gpar(col=col,lwd=lwd))
           }

           ##Uncomment for base graphics
           else{
              par(xpd=TRUE)
              points(x1,y1,type='l',col=col,lwd=lwd)
              par(xpd=FALSE)
           }

}


library(ggplot2)
x <- c(runif(10),runif(10)+2)
y <- c(runif(10),runif(10)+2)
qplot(x=x,y=y) +
  scale_x_continuous("",breaks=c(.5,2.5),labels=c("Low types","High types") )

curly(N=100,Tilt=0.4,Long=0.3,scale=0.025,xcent=0.2525,
      ycent=par()$usr[3]+0.1,theta=-pi/2,col="red",lwd=2,grid=TRUE)
curly(N=100,Tilt=0.4,Long=0.3,scale=0.025,xcent=0.8,
      ycent=par()$usr[3]+0.1,theta=-pi/2,col="red",lwd=2,grid=TRUE)