转置行、列和组[重复]

Question

我有一个 DF，我想转置行和列并对 ID 的数量进行分组（不同计数）。我的例子：

ID<- c(111,222,111,222,333,111,222,333)
AGE_GROUP<- c("30_40","30_40","30_40","30_40","50_60","30_40","30_40","50_60")
DATE<-c("JAN","JAN","FEB","FEB","FEB","MAR","MAR","MAR")
DF<-data.frame(ID,AGE_GROUP,DATE)

我想要的结果。我的新DF：

AGE_GROUP<- c("30_40","50_60")
JAN<- c(2,0)
FEB<- c(2,1)
MAR<- c(2,1)
DF2<-data.frame(AGE_GROUP,JAN,FEB,MAR)

我将如何进行这种分组和转置？

Answer 1

删除“ID”列后，我们使用pivot_wider 和values_fn

library(dplyr)
library(tidyr)
DF %>% 
  select(-ID) %>% 
  pivot_wider(names_from = DATE, values_from = DATE, 
     values_fn = length, values_fill = 0)

-输出

# A tibble: 2 x 4
#  AGE_GROUP   JAN   FEB   MAR
#  <chr>     <int> <int> <int>
#1 30_40         2     2     2
#2 50_60         0     1     1

---

在base R，table 会更容易

table(DF[-1])