why do you use 365.25?
dates<-as.character(data[,"date_commissioned"]); # convert dates to characters #dates[1:10] #[1] "19910101" "19860101" "19910101" "19860101" "19910101" "19910101" "19910101" "19910101" "19910101" "19910101" dateObs <- as.Date(dates,format="%Y%m%d") #dateObs[1:10] #[1] "1991-01-01" "1986-01-01" "1991-01-01" "1986-01-01" "1991-01-01" "1991-01-01" "1991-01-01" "1991-01-01" "1991-01-01" "1991-01-01" today <- Sys.Date() x.date <- as.Date(dateObs, format="%Y%m%d") AGE <- round(as.vector(difftime(today , x.date, units='day') / 365.25)) frenchcr wrote: > > > it sure does thank you! > > >> will this work for you >> >> x <- c('19910101', '19950302', '20010502') >> today <- Sys.Date() >> x.date <- as.Date(x, format="%Y%m%d") >> round(as.vector(difftime(today , x.date, units='day') / 365.25)) > [1] 19 15 9 >> > > > On Sun, Nov 8, 2009 at 2:44 PM, <frenc...@btinternet.com> wrote: >> Hi Jim, >> >> Thanks for the quick reply...not sure what you mean by frame of >> reference(only been using R for 4 days)...to clarify, i need to turn my >> dates from 1999-10-01 into 1999 then i subtract 2009 -1999 to get an age >> of 10. The column im working on has 312,000 rows and some have NA in them >> as we have no dates for that item. >> >> To recap, the column is just a bunch of dates with some field empty, i >> want to change the column from "date of commision" to "age of asset" >> >> Cheers >> Chris. > > > > > jholtman wrote: >> >> What is the frame of reference to determine the age? Check out >> 'difftime'. >> >> On Sun, Nov 8, 2009 at 1:50 PM, frenchcr <frenc...@btinternet.com> wrote: >>> >>> Ive got a big column of dates (also some fields dont have a date so they >>> have >>> NA instead), >>> that i have converted into date format as so... >>> >>> >>> dates<-as.character(data[,"date_commissioned"]); # converted dates to >>> characters >>> dates[1:10] >>> [1] "19910101" "19860101" "19910101" "19860101" "19910101" "19910101" >>> "19910101" "19910101" "19910101" "19910101" >>> >>> dateObs <- as.Date(dates,format="%Y%m%d") >>> dateObs[1:10] >>> [1] "1991-01-01" "1986-01-01" "1991-01-01" "1986-01-01" "1991-01-01" >>> "1991-01-01" "1991-01-01" "1991-01-01" "1991-01-01" "1991-01-01" >>> >>> >>> >>> Now i need to turn the dates into AGE, how do i do it? Im not worried >>> about >>> fractions of years, whole years would do. >>> >>> >>> -- >>> View this message in context: >>> http://old.nabble.com/Turn-dates-into-age-tp26256656p26256656.html >>> Sent from the R help mailing list archive at Nabble.com. >>> >>> ______________________________________________ >>> R-help@r-project.org mailing list >>> https://stat.ethz.ch/mailman/listinfo/r-help >>> PLEASE do read the posting guide >>> http://www.R-project.org/posting-guide.html >>> and provide commented, minimal, self-contained, reproducible code. >>> >> >> >> >> -- >> Jim Holtman >> Cincinnati, OH >> +1 513 646 9390 >> >> What is the problem that you are trying to solve? >> >> ______________________________________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> >> > > -- View this message in context: http://old.nabble.com/Turn-dates-into-age-tp26256656p26257435.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.