按日和月选择时间段

Question

I have a dataframe organized by year. For example: date <- seq(as.Date("2001-07-20"),as.Date("2010-12-31"),by = 1)
Now I want to select a subset by using two time periods: June 23 to July 13 AND July 20 to Aug 9 for 2004-2008. Could you provide some clue? Thanks!

Yes, it can be solved by: test[date %between% c("2004-07-20", "2004-08-09")]... but there are many years in my data, the code can be very repetitive. I wonder if it can be solved like:

df$md <- format(as.Date(df$date), "%m-%d") df <- df[df$md %in% c(as.Date(06-23):Date(07-13), Date(07-20):Date(08-09)) & year %in% (2004:2008),]

It doesn't work: Error in as.Date.numeric(6 - 23) : 'origin' must be supplied

Answer 1

You can construct the ranges of interest and subset:

library(lubridate)    
date <- seq(as.Date("2001-07-20",origin="1970-01-01"),as.Date("2010-12-31",origin="1970-01-01"),by = 1) 

range1 <- as.Date(unlist(lapply(c(0:4),function(y) seq(as.Date("2004-06-23",origin="1970-01-01"),as.Date("2004-07-13",origin="1970-01-01"),by="1 day") + years(y))),origin="1970-01-01")
range2 <- as.Date(unlist(lapply(c(0:4),function(y) seq(as.Date("2004-07-20",origin="1970-01-01"),as.Date("2004-08-09",origin="1970-01-01"),by="1 day") + years(y))),origin="1970-01-01")

date[date %in% range1 | date %in% range2]

Alternative

Alternative answer using %between% as suggested in OP

library(lubridate)
dates <- seq(as.Date("2001-07-20"),as.Date("2010-12-31"),by = 1)

r1 <- c(as.Date("2004-06-23"),as.Date("2004-07-13"))
r2 <- c(as.Date("2004-07-20"),as.Date("2004-08-09"))

ranges <- lapply(c(0:4),function(y) list(r1=r1 + years(y),r2=r2+years(y)))
as.Date(unlist(lapply(ranges,function(r) { dates[dates %between% r$r1 | dates %between% r$r2] })))