Thanks All. Your idea is useful!!! On Tue, Oct 7, 2014 at 1:01 PM, Jim Lemon <j...@bitwrit.com.au> wrote:
> On Tue, 7 Oct 2014 11:51:34 AM Göran Broström wrote: > > On 2014-10-07 11:27, Jim Lemon wrote: > > > On Tue, 7 Oct 2014 10:32:42 AM Frederic Ntirenganya wrote: > > >> Dear All, > > >> > > >> How can I change the format of date of day of the year ? for > > > > > > example r > > > > > >> (i.e. "17 Apr" rather than "108"). > > >> > > >> The following is the type of the dataset I have > > >> > > >> head(Samaru) > > >> > > >> Year Start End Length > > >> > > >> 1 1930 108 288 180 > > >> 2 1931 118 288 170 > > >> 3 1932 115 295 180 > > >> 4 1933 156 294 138 > > >> 5 1934 116 291 175 > > >> 6 1935 134 288 154 > > > > > > Hi Frederic, > > > The easiest method I can think of is this: > > > > > > Samaru$Start<-format(as.Date( > > > > > > paste(Samaru$Year,"01-01",sep="-"))+Samaru$Start, > > > "%b %d") > > > > > > Samaru$End<-format(as.Date( > > > > > > paste(Samaru$Year,"01-01",sep="-"))+Samaru$End, > > > "%b %d") > > > > In the package 'eha' I have a function 'toDate': > > > require(eha) > > > toDate(1930 + 108/365) > > > > [1] "1930-04-19" > > > > (Interestingly, we are all wrong; the correct answer seems to be > > "1930-04-18") > > > > > toDate > > > > function (times) > > { > > if (!is.numeric(times)) > > stop("Argument must be numeric") > > times * 365.2425 + as.Date("0000-01-01") > > } > > > > The 'inverse' function is 'toTime'. > > > > Sometimes it misses by one day; not very important in my > applications, > > but may be otherwise. > > > Hi Goran, > You're correct. > > as.Date("Apr 19 1930","%b %d %Y") - > + as.Date("Jan 1 1930","%b %d %Y") > Time difference of 108 days > > The t > > Samaru$Start<-format(as.Date( > paste(Samaru$Year,"01-01",sep="-"))+Samaru$Start-1,"%b %d") > Samaru$End<-format(as.Date( > paste(Samaru$Year,"01-01",sep="-"))+Samaru$End-1, "%b %d") > > Jim > > ______________________________________________ > 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. > -- Frederic Ntirenganya Maseno University, Kenya. Mobile:(+254)718492836 Email: fr...@aims.ac.za https://sites.google.com/a/aims.ac.za/fredo/ [[alternative HTML version deleted]] ______________________________________________ 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.