R计算没有特定符号的唯一值

发布于08月30日

我有一个数据帧‘df’，它有分类列和POSIXct列.这些数据如下所示:

Category	DateTime
A	2022-08-29 00:00:00
A	2022-08-29 00:00:00
A 1	2022-08-29 00:00:00
A 1	2022-08-29 00:00:00
A 1	2022-08-29 00:00:00
B	2022-08-29 00:00:00
B	2022-08-29 00:00:00
B	2022-08-29 00:00:00
B 1	2022-08-29 00:00:00
B 1	2022-08-29 00:00:00
B 1	2022-08-29 00:00:00
B 1	2022-08-29 00:00:00
B 1	2022-08-29 00:00:00
A	2022-08-29 02:00:00
A 1	2022-08-29 02:00:00
B	2022-08-29 02:00:00
B	2022-08-29 02:00:00
B	2022-08-29 02:00:00
B 1	2022-08-29 02:00:00
B 1	2022-08-29 02:00:00
B 1	2022-08-29 02:00:00

我想创建一个新的数据帧‘df2’，它计算列‘Category’中不以"1"结尾的列‘DateTime’中的每个唯一值，结果如下所示:

Category	DateTime	CatCount
A	2022-08-29 00:00:00	2
B	2022-08-29 00:00:00	3
A	2022-08-29 02:00:00	1
B	2022-08-29 02:00:00	3

推荐答案

我们可以filter输出具有1的行，然后执行count

library(dplyr)
library(stringr)
df1 %>%
   filter(str_detect(Category, "\\s+1", negate = TRUE)) %>%
   count(Category, DateTime, name = "CatCount")

-输出

 Category            DateTime CatCount
1        A 2022-08-29 00:00:00        2
2        A 2022-08-29 02:00:00        1
3        B 2022-08-29 00:00:00        3
4        B 2022-08-29 02:00:00        3

数据

df1 <- structure(list(Category = c("A", "A", "A 1", "A 1", "A 1", "B", 
"B", "B", "B 1", "B 1", "B 1", "B 1", "B 1", "A", "A 1", "B", 
"B", "B", "B 1", "B 1", "B 1"), DateTime = c("2022-08-29 00:00:00", 
"2022-08-29 00:00:00", "2022-08-29 00:00:00", "2022-08-29 00:00:00", 
"2022-08-29 00:00:00", "2022-08-29 00:00:00", "2022-08-29 00:00:00", 
"2022-08-29 00:00:00", "2022-08-29 00:00:00", "2022-08-29 00:00:00", 
"2022-08-29 00:00:00", "2022-08-29 00:00:00", "2022-08-29 00:00:00", 
"2022-08-29 02:00:00", "2022-08-29 02:00:00", "2022-08-29 02:00:00", 
"2022-08-29 02:00:00", "2022-08-29 02:00:00", "2022-08-29 02:00:00", 
"2022-08-29 02:00:00", "2022-08-29 02:00:00")),
class = "数据.frame", row.names = c(NA, 
-21L))