R help - Oct 2009 - Year and Month extraction from Date object.

Hello,

I have seen much discussion on Date. But I can't seem to do this simple
operation. I can convert a string to a date:

d <- as.Date(DATE, format="%m/%d/%Y")

But what I want to do is extract the year and month so I can construct an
element in a ts object. Ideally I would like to see d$year but that doesn't
seem to be available. Once I have a Date object how can I get an integer year?

Thank you.

Kevin

?weekdays contains

Note:

      Other components such as the day of the month or the year are very
      easy to compute: just use ?as.POSIXlt? and extract the relevant
      component.

(d <- Sys.Date())
1900 + as.POSIXlt(d)$year
1 + as.POSIXlt(d)$mon

should get you started.

On Tue, 27 Oct 2009, rkevinburton at charter.net wrote:
> Hello,
>
> I have seen much discussion on Date. But I can't seem to do this 
> simple operation. I can convert a string to a date:
>
> d <- as.Date(DATE, format="%m/%d/%Y")
>
> But what I want to do is extract the year and month so I can 
> construct an element in a ts object. Ideally I would like to see 
> d$year but that doesn't seem to be available. Once I have a Date 
> object how can I get an integer year?
>
> Thank you.
>
> Kevin
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

On Tue, 2009-10-27 at 14:49 -0700, rkevinburton at charter.net
wrote:
> Hello,
> 
> I have seen much discussion on Date. But I can't seem to do this
> simple operation. I can convert a string to a date:
> 
> d <- as.Date(DATE, format="%m/%d/%Y")
> 
> But what I want to do is extract the year and month so I can construct
> an element in a ts object. Ideally I would like to see d$year but that
> doesn't seem to be available. Once I have a Date object how can I get
> an integer year?
as.numeric(format(d, format = "%Y"))
as.numeric(format(d, format = "%m"))

and so on.

Look at the formats in ?strftime for further details.

HTH

G
> 
> Thank you.
> 
> Kevin
> 
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