Extract year from string and text data

Question

I need extract start year and end year from a vector with values of these nature.

 yr<- c("June 2013 – Present (2 years 9 months)", "January 2012 – June 2013 (1 year 6 months)","2006 – Present (10 years)","2002 – 2006 (4 years)")


 yr
 June 2013 – Present (2 years 9 months)
 January 2012 – June 2013 (1 year 6 months)
 2006 – Present (10 years)
 2002 – 2006 (4 years)

I am expecting output like this. Does anyone have suggestions?

 start_yr       end_yr

2013            2016
2012            2013
2006            2016
2002            2006

gsub "present" with 2016 and extract four digit numbers. try it — rawr, Feb 29 '16 at 21:58

score 5 · Accepted Answer · edited Feb 29 '16 at 22:26

5

x <- gsub("present", "2016", yr, ignore.case = TRUE)
x <- regmatches(x, gregexpr("\\d{4}", x))
start_yr <- sapply(x, "[[", 1)
end_yr <- sapply(x, "[[", 2)

this saves the start year and end year in 2 separate variables, if you want them in one just edit the code and make y$start_yr y$end_yr

edited Feb 29 '16 at 22:26

nrussell

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answered Feb 29 '16 at 22:14

Antoine

76
5

1

I have this thing called "character(0)" which is creeping up and getting this error "Error in FUN(X[[i]], ...) : subscript out of bounds". Any suggestions on removing that rows? – user3570187 Feb 29 '16 at 22:52

cderv · Answer 2 · 2016-03-01T17:28:59.667

0

Another solution is to use the stringr package

library(stringr)
x <- str_replace(yr, "Present", 2016)
DF <- as.data.frame(str_extract_all(x, "\\d{4}", simplify = T))
names(DF) <- c("start_yr", "end_yr")
DF

and you will get

      start_yr end_yr
1     2013   2016
2     2012   2013
3     2006   2016
4     2002   2006

edited Mar 01 '16 at 17:28

answered Feb 29 '16 at 22:57

cderv

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Extract year from string and text data

2 Answers2