ggplot2 geombar（）和binwidth

Question

我开始使用ggplot并尝试使用此example：

library(ggplot2)
set.seed(6298) 
diamonds_small <- diamonds[sample(nrow(diamonds), 1000), ] 
hist_cut <- ggplot(diamonds_small, aes(x=price, fill=cut))
hist_cut + geom_bar() # defaults to stacking

关于我的数据：

a4<-structure(list(MAACP = c(2.81, 2.28, 2.38, 3.96, 1.99, 4.69, 
3.07, 3.41, 4.18, 1.67, 3.88, 2.89, 3.32, 4.15, 5.53, 2.19, 2.36, 
5.07, 3.18, 1.58, 2.81, 3.09, 4.9, 3.69, 3.48, 4.58, 4.54, 3.42, 
2.92, 3.83, 3.42, 2.51, 2.95, 3.97, 2.95, 5.55, 5.54, 3.39, 0, 
2.06, 5.21, 2.64, 5.66, 2.15, 3.87, 4.09, 2.81, 5.19, 3.55, 5.17, 
3.55, 2.19, 3.51, 4.9, 4.95, 2.91, 3.61, 3.06, 3.02, 3.49, 3.14, 
4.23, 4.11, 2.36, 2.81, 2.82, 2.94, 4.17, 4.14, 4.35, 3.52, 3.35, 
5.45, 3.41, 4.31, 4.31, 2.45, 3.35, 4.11, 3.21, 2.52, 4.91, 3.92, 
4.84, 2.84, 2.95, 2.98, 3.67, 4.75, 3.62, 2.88, 3.09, 3.36, 3.29, 
2.47, 3.59, 3.59, 2.6, 1.85, 5.06), type = structure(c(1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 
1L, 1L), .Label = c("1", "2"), class = "factor")), .Names = c("MAACP", 
"type"), row.names = c(NA, 100L), class = "data.frame")

不幸的是，我无法获得显示直方图的情节。

hist_cut<-ggplot(a4,aes(x="MAACP",fill=type),binwidth=.1)
hist_cut+geom_bar()

更改binwidth没有任何区别：

hist_cut<-ggplot(a4,aes(x="MAACP",fill=type),binwidth=.1)
hist_cut+geom_bar(binwidth=0.1)

Answer 1

好的，似乎geom_bar默认情况下会生成一个直方图，只传递一个x变量。没有人知道这一点并且不太喜欢它。

无论如何：

1. 如果您不使用aes_string，请不要引用变量名称。

2. 将binwidth传递给geom_bar，并将其传递给stat_bin。

像这样：

hist_cut <- ggplot(a4, aes(x = MAACP, fill = type))
hist_cut + geom_bar(binwidth = .1)