Question

我在数据框中有一个因子。我想从长度最长（大多数条目）到最短长度的那些因素中排序因子的水平（该因子水平的最少条目。

 df<- data.frame(x= c("B","B","B","A","A","C","C","C","C"), y= c( 
 "2", "2", "2","1","1","3","3","3","3"))

我的输出是：

df<- data.frame(x= c("C","C", "C","C","B","B","B","A","A",), y= c( 
 "3","3","3","3", "2", "2","2","1","1",))

我试过了：

A.data$loc<-sort(length(A.data$loc))

Answer 1

这是使用dplyr的另一种方式：

require(dplyr)
require(magrittr)

df %>%
  group_by(x) %>%
  mutate(count = n()) %>%
  arrange(desc(count)) %>%
  select(-count)

输出结果为：

       x      y
  <fctr> <fctr>
1      C      3
2      C      3
3      C      3
4      C      3
5      B      2
6      B      2
7      B      2
8      A      1
9      A      1

Answer 2

我们可以使用library(data.table) setDT(df)[, n := .N, x][order(-n)][, n := NULL][] # x y #1: C 3 #2: C 3 #3: C 3 #4: C 3 #5: B 2 #6: B 2 #7: B 2 #8: A 1 #9: A 1

执行此操作

table

或base R

中的

df[with(df, order(factor(x, levels = names(sort(table(x), decreasing = TRUE))))),]

set(gca,'Ycolor',fig.color,'Ycolor',fig.color)

按因子长度排序

2 个答案: