Check if a date is within an interval in R

Question

I have these three intervals defined:

YEAR_1  <- interval(ymd(\'2002-09-01\'), ymd(\'2003-08-31\'))
YEAR_2  <- interval(ymd(\'2003-09-01\'), ymd(\'20         


        

Answer 1

With lubridate and mapply:

library(lubridate)

dates <- # your data here

# no idea how you generated these, so let's just copy them
YEAR_1 <- interval(ymd('2002-09-01'), ymd('2003-08-31'))
YEAR_2 <- interval(ymd('2003-09-01'), ymd('2004-08-31')) 
YEAR_3 <- interval(ymd('2004-09-01'), ymd('2005-08-31'))

# this should scale nicely
sapply(c(YEAR_1, YEAR_2, YEAR_3), function(x) { mapply(`%within%`, dates, x) })

The result is a matrix with one column per interval:

        [,1]  [,2]  [,3]
  [1,]  TRUE FALSE FALSE
  [2,] FALSE  TRUE FALSE
  [3,] FALSE  TRUE FALSE
  [4,] FALSE  TRUE FALSE
  ... etc. (100 rows in your example data)

There might be a nicer way to code that with purrr, but I am too novice to purrr to see it.