[R] Truncating dates (and other date-time manipulations)

[Gabor Grothendieck]

See ?cut.Date

In the zoo package see:
?as.yearmon
?as.yearqtr
?aggregate.zoo

and the many examples in:
?plot.zoo
?xyplot.zoo
as well as the three zoo vignettes.

Also in the xts package look at
?to.period

For regularly spaced series the tis package supports a wide
variety of time bases and can convert among them.

There are as.zoo.tis and as.tis.zoo routines in zoo and tis; also,
xts is a subclass of zoo so all these packages can work together.


On Thu, Sep 11, 2008 at 11:02 AM, hadley wickham <h.wickham at gmail.com> wrote:
> Dear all,
>
> I've been struggling to perform common operations on dates that I need
> to be able to correct draw date-time scales - in particular I need to
> be able to round/truncate/ceiling dates to arbitrary precision - e.g.
> to weeks, months or years (or multiples thereof).  I haven't been able
> to find anything to do this in base R (trunc.Date only truncates to
> sub-day units), or in the date related contributed packages I've
> looked in (e.g. chron).  Have I missed something?
>
> Otherwise, I have been working on a bottom up set of functions to make
> date manipulation easier - http://gist.github.com/10238.  These should
> work for all date-time types and I've tried to use a consistent naming
> scheme and consistent output conventions.  This seems like a rather
> small bundle of functions to be worth turning into a package, so I was
> wondering if anyone would be interested in adopting them into an
> existing date-time related package.
>
> Regards,
>
> Hadley
>
> --
> http://had.co.nz/
>
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