r - ggplot2 上的分面直方图中的单个 binwidths

Question

我用 facet_grid 做了一系列直方图并且我希望网格中的每个直方图都具有相同数量的类，在下面的示例中，例如6个类。下面这个例子中的问题是 binwidth = diff(range(x$data))/6)根据 a、b 和 c 的整体范围定义类，即为所有三个方面定义一个 binwidth。

我如何为方面 a、b 和 c 单独定义 binwidth？

require("ggplot2")

a <- c(1.21,1.57,1.21,0.29,0.36,0.29,0.93,0.26,0.28,0.48,
       0.12,0.38,0.83,0.82,0.41,0.69,0.25,0.98,0.52,0.11)
b <- c(0.42,0.65,0.17,0.38,0.44,0.01,0.01,0.03,0.15,0.01)
c <- c(1.09,3.55,1.07,4.55,0.55,0.11,0.72,0.66,1.22,3.04,
       2.01,0.64,0.47,1.33,3.44)

x <- data.frame(data = c(a,b,c), variable = c(rep("a",20),rep("b",10),rep("c",15)),area="random")

qplot(data, data = x, geom = "histogram", binwidth = diff(range(x$data))/6) +
  facet_grid(area~variable, scales = "free")

Answer 1

这不是最佳的，但您可以在不同的层中进行直方图:

ggplot(x, aes(x=data)) +
   geom_histogram(data=subset(x, variable=="a"), binwidth=.1) +
   geom_histogram(data=subset(x, variable=="b"), binwidth=.2) +
   geom_histogram(data=subset(x, variable=="c"), binwidth=.5) +
   facet_grid(area~variable, scales="free")