CODEWITHSUNDEEP
rdate
Eva
Eva

Reputation: 851

How to change year format

I have a year column in my dataframe, which is formatted as financial year (e.g. 2015-16, 2016-17, etc). I want to change them to just 4-digit year in such a way that 2015-16 becomes 2016; 2016-17 becomes 2017, etc. How can I do it?

Upvotes: 1

Views: 70

Answers (3)

akrun
akrun

Reputation: 886938

We can use sub to capture the first two digits while leaving the next two digits and the -, and in the replacement, specify the backreference (\\1) of the captured group

as.numeric(sub("^(\\d{2})\\d{2}-", "\\1", v1))
#[1] 2016 2017

Or more compactly match the two digits followed by the -, and replace with blank ('')

sub("\\d{2}-", "", v1)
[1] "2016" "2017"

Or using substr

paste0(substr(v1,1, 2), substr(v1, 6, 7))
#[1] "2016" "2017"

NOTE: None of the solutions require any external packages. Also, it doesn't implicitly assume there is always an increment of 1 year. It can be any year range as below and it works

v2 <- c("2015-18", "2014-15", "2012-19")
sub("\\d{2}-", "", v2)
#[1] "2018" "2015" "2019"

data

v1 <- c("2015-16", "2016-17")

Upvotes: 0

Ronak Shah
Ronak Shah

Reputation: 388807

You can use parse_number from readr :

x <- c('2015-16', '2016-17')
readr::parse_number(x) + 1
#[1] 2016 2017

parse_number drops any non-numeric characters before or after the first number. So in this example, everything after the first number is dropped and turned to numeric. We then add 1 to to it to get next year.

Upvotes: 2

Sotos
Sotos

Reputation: 51582

A possible solution can be,

as.numeric(sub('-.*', '', '2015-16')) + 1
#[1] 2016

Upvotes: 1

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