Re: [R] Turn dates into age

2009-11-08 Thread Marc Schwartz
> Sys.Date() [1] "2009-11-08" > as.Date("05/29/1971", format = "%m/%d/%Y") [1] "1971-05-29" > as.numeric((Sys.Date() - as.Date("05/29/1971", format = "%m/%d/ %Y")) / 365.25) [1] 38.44764 or perhaps more clearly: EndDate <- Sys.Date() StartDate <- as.Date("05/29/1971", format = "%m/%d/%Y")

Re: [R] Turn dates into age

2009-11-08 Thread Jim Burke
To clarify. Lets turn a date into an age. Given 05/29/1971 in mm/dd/ format. What is the year difference between then and today? This would be the "age" requested that starts 05/29/1971 as one. Thanks, Jim David Winsemius wrote: > > On Nov 8, 2009, at 3:11 PM, frenchcr wrote: > >> >> >> w

Re: [R] Turn dates into age

2009-11-08 Thread David Winsemius
On Nov 8, 2009, at 3:11 PM, frenchcr wrote: why do you use 365.25? As opposed to what? -- David dates<-as.character(data[,"date_commissioned"]); # convert dates to characters #dates[1:10] #[1] "19910101" "19860101" "19910101" "19860101" "19910101" "19910101" "19910101" "19910101" "199

Re: [R] Turn dates into age

2009-11-08 Thread frenchcr
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] "1

Re: [R] Turn dates into age

2009-11-08 Thread frenchcr
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, wrote: > Hi Jim, >

Re: [R] Turn dates into age

2009-11-08 Thread Marc Schwartz
As Jim has noted, if the dates you have below are an 'end date', you need to define the time0 or start date for each to calculate the intervals. On the other hand, are the dates you have below the start dates and you need to calculate the time to today? In the latter case, see ?Sys.Date to

Re: [R] Turn dates into age

2009-11-08 Thread jim holtman
What is the frame of reference to determine the age? Check out 'difftime'. On Sun, Nov 8, 2009 at 1:50 PM, frenchcr 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

[R] Turn dates into age

2009-11-08 Thread frenchcr
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" "199