CODEWITHSUNDEEP
r
JohnBones JohnBones
JohnBones JohnBones

Reputation: 343

In R how to create a year vector with a simple rule

I have the first year as 2007. The last year is 2021

I need to create a character vector just like the vector bellow:

c("2007-2008","2007-2010","2007-2012","2007-2014","2007-2016","2007-2018","2007-2021")

The idea is to have: first-year -second year, first-year - first-year+3, first-year - first-year+5, first-year - first-year+7, first-year - first-year+9, first-year - first-year+11, first-year - first-year+13 But when I have first-year - first-year+13 and the next step is bigger than the last year (2021) I consider first-year - lastyear

In other words the difference between the last years should be at least 2 (2008....2010...2012...2014..2016...2018...2020) But once I have 2020 it will lead the next interval 2007-2021 have a difference of 1 year, if this happens I consider 2007-2018and 2007-2021

How can I create something like this in R?

Upvotes: 0

Views: 45

Answers (2)

Andre Wildberg
Andre Wildberg

Reputation: 19163

An idea to generate the required sequence directly from seq

st <- 2007
en <- 2021

paste(st, unique(c(seq(st + 1, en - 2, 2), en)), sep = "-")
[1] "2007-2008" "2007-2010" "2007-2012" "2007-2014" "2007-2016" "2007-2018"
[7] "2007-2021"

Upvotes: 1

r2evans
r2evans

Reputation: 160607

years <- c(2007, 2021)
years <- unique(sort(c(years, seq(1 + years[1], years[2], by = 2))))
years
# [1] 2007 2008 2010 2012 2014 2016 2018 2020 2021
years <- years[c(diff(years) >= 2, TRUE)]
years
# [1] 2008 2010 2012 2014 2016 2018 2021
paste(2007, years, sep = "-")
# [1] "2007-2008" "2007-2010" "2007-2012" "2007-2014" "2007-2016" "2007-2018" "2007-2021"

Upvotes: 1

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