R 如何避免绘图中的空因子级别？

用户

我有这个数据框：

A<- c(10,2,4,5,3,5,98,65,36,65,6,100,70,54,25,23,22,30,15,23)
B<- c(1,0.1,0.5,0.8,0.2,0.9,3,1.2,5.6,3.5,15.9,10.2,5,5.1,7.1,5,6,10,4,8)
C<- c("a","a","a","a","a","a","b","b","b","b","c","c","c","c","d","d","d","d","d","d")
mydf<- data.frame(A,B,C)

如何绘制子集数据帧以避免删除级别

谢谢大家!

只要做：

plot(B~ droplevels(C), data=subset)

只要做：

plot(B~ droplevels(C), data=subset)

---

使用

液滴液位

：

subset$C <- droplevels(subset$C)
plot(B~ C, data=subset)

---

subset$C使用
droplevels
：

subset$C <- droplevels(subset$C)
plot(B~ C, data=subset)

子集$C
通过
factor
删除缺失的因子级别：

subset$C <- factor(subset$C)

str(subset)
#'data.frame':   6 obs. of  3 variables:
#$ A: num  10 2 4 5 3 5
#$ B: num  1 0.1 0.5 0.8 0.2 0.9
#$ C: Factor w/ 1 level "a": 1 1 1 1 1 1

子集$C
通过
factor
删除缺失的因子级别：

subset$C <- factor(subset$C)

str(subset)
#'data.frame':   6 obs. of  3 variables:
#$ A: num  10 2 4 5 3 5
#$ B: num  1 0.1 0.5 0.8 0.2 0.9
#$ C: Factor w/ 1 level "a": 1 1 1 1 1 1

subset$C我同意，我想更改子集名称，但答案比我的编辑更快。谢谢JilberI同意，我想更改子集名称，但答案比我的编辑更快。谢谢Jilberso轻松！谢谢你，这么简单！谢谢JT85