网格/视口方法可以像这样工作。首先,我们安排一些数据以匹配您显示的内容。正如您在问题中指定的那样,我们会轮换 X、Y 和 Z 中的每一个的因子水平
## Your data
dat <- data.frame(X = factor(rep(LETTERS[1:4], times = c(10,20,30,40)),
levels = LETTERS[1:4]),
Y = factor(rep(LETTERS[1:4], times = c(20,30,40,10)),
levels = LETTERS[c(4,1:3)]),
Z = factor(rep(LETTERS[1:4], times = c(30,40,10,20)),
levels = LETTERS[c(3:4,1:2)]))
接下来我们生成单独的饼图,旋转相同的scale_fill_manual() 颜色,以我们旋转数据中的级别的相同顺序,dat(为讨厌的颜色道歉 - 如何获得第一个 n ggplot 会正常使用的颜色?):
p1 <- ggplot(dat, aes(x = factor(1), fill = factor(X))) +
geom_bar(width = 1) + coord_polar(theta = "y") +
scale_fill_manual(value = c("red","green","yellow","blue"))
p2 <- ggplot(dat, aes(x = factor(1), fill = factor(Y))) +
geom_bar(width = 1) + coord_polar(theta = "y") +
scale_fill_manual(value = c("red","green","yellow","blue")[c(4,1:3)])
p3 <- ggplot(dat, aes(x = factor(1), fill = factor(Z))) +
geom_bar(width = 1) + coord_polar(theta = "y") +
scale_fill_manual(value = c("red","green","yellow","blue")[c(3:4,1:2)])
现在我们需要一个新的绘图页面并在其上推送一个 2x2 布局:
grid.newpage()
pushViewport(viewport(layout = grid.layout(2,2)))
自定义函数允许我们为每个后续绘图简化设置行/列:
vplayout <- function(x, y) {
viewport(layout.pos.row = x, layout.pos.col = y)
}
接下来,我们只需在正确的视口上绘制每个保存的 ggplot 对象,由参数 vp 指定:
print(p1, vp = vplayout(1,1))
print(p2, vp = vplayout(1,2))
print(p3, vp = vplayout(2,1))
上面的网格代码取自 Hadley 关于 ggplot 的优秀书籍的第 94 页。
这会产生: