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
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