按年份在R中按日期进行子集。

Question

我的数据如下：

site year date
A    2019 2019-08-08
A    2019 2019-08-18
A    2019 2019-10-14
A    2019 2019-10-27
B    2019 2019-08-07
B    2019 2019-08-19
B    2019 2019-10-15
B    2019 2019-10-20
A    2020 2020-08-08
A    2020 2020-08-18
A    2020 2020-10-14
A    2020 2020-10-27
B    2020 2020-08-07
B    2020 2020-08-19
B    2020 2020-10-15
B    2020 2020-10-20

我希望针对每一年，筛选出满足以下条件的行：

日期在8月15日及之后，并且在10月15日及之前。

谢谢您提前的帮助！

- novice_coder

Answer 1

转换为一年中的第几天，使用filter

library(dplyr)
library(lubridate)
df1 %>% 
  mutate(date = ymd(date)) %>% 
  filter(between(yday(date), 228, 289))

-输出

 site year       date
1    A 2019 2019-08-18
2    A 2019 2019-10-14
3    B 2019 2019-08-19
4    B 2019 2019-10-15
5    A 2020 2020-08-18
6    A 2020 2020-10-14
7    B 2020 2020-08-19
8    B 2020 2020-10-15

数据

df1 <- structure(list(site = c("A", "A", "A", "A", "B", "B", "B", "B", 
"A", "A", "A", "A", "B", "B", "B", "B"), year = c(2019L, 2019L, 
2019L, 2019L, 2019L, 2019L, 2019L, 2019L, 2020L, 2020L, 2020L, 
2020L, 2020L, 2020L, 2020L, 2020L), date = c("2019-08-08", "2019-08-18", 
"2019-10-14", "2019-10-27", "2019-08-07", "2019-08-19", "2019-10-15", 
"2019-10-20", "2020-08-08", "2020-08-18", "2020-10-14", "2020-10-27", 
"2020-08-07", "2020-08-19", "2020-10-15", "2020-10-20")), 
class = "data.frame", row.names = c(NA, 
-16L))

- akrun