From rpeng at jhsph.edu  Tue Mar 18 19:09:20 2008
From: rpeng at jhsph.edu (Roger D. Peng)
Date: Tue, 18 Mar 2008 14:09:20 -0400
Subject: [Rd] cut.Date and cut.POSIXt problem
In-Reply-To: <971536df0803181004x5ebbe960q6879506089b3e428@mail.gmail.com>
References: <971536df0803181004x5ebbe960q6879506089b3e428@mail.gmail.com>
Message-ID: <47E00550.8050602@jhsph.edu>

Seems it did work as advertised in R 2.6.0 but is still broken in R-devel.  Will 
take a look.

-roger

Gabor Grothendieck wrote:
> cut.Date and cut.POSIXt indicate that the breaks argument
> can be an integer followed by a space followed by "year", etc.
> but it seems the integer is ignored.
> 
> For example, I assume that breaks = "3 months" is supposed
> to cut it into quarters but, in fact, it cuts it into months as if
> 3 had not been there.
> 
>> d <- seq(Sys.Date(), length = 12, by = "month")
>> cut(d, "3 months")
>  [1] 2008-03-01 2008-04-01 2008-05-01 2008-06-01 2008-07-01 2008-08-01
> 2008-09-01 2008-10-01 2008-11-01 2008-12-01 2009-01-01 2009-02-01
> Levels: 2008-03-01 2008-04-01 2008-05-01 2008-06-01 2008-07-01
> 2008-08-01 2008-09-01 2008-10-01 2008-11-01 2008-12-01 2009-01-01
> 2009-02-01
>> cut(as.POSIXct(d), "3 months")
>  [1] 2008-03-01 2008-04-01 2008-05-01 2008-06-01 2008-07-01 2008-08-01
> 2008-09-01 2008-10-01 2008-11-01 2008-12-01 2009-01-01 2009-02-01
> Levels: 2008-03-01 2008-04-01 2008-05-01 2008-06-01 2008-07-01
> 2008-08-01 2008-09-01 2008-10-01 2008-11-01 2008-12-01 2009-01-01
> 2009-02-01
>> cut(as.POSIXlt(d), "3 months")
>  [1] 2008-03-01 2008-04-01 2008-05-01 2008-06-01 2008-07-01 2008-08-01
> 2008-09-01 2008-10-01 2008-11-01 2008-12-01 2009-01-01 2009-02-01
> Levels: 2008-03-01 2008-04-01 2008-05-01 2008-06-01 2008-07-01
> 2008-08-01 2008-09-01 2008-10-01 2008-11-01 2008-12-01 2009-01-01
> 2009-02-01
> 
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> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
> 

-- 
Roger D. Peng  |  http://www.biostat.jhsph.edu/~rpeng/



[Rd] cut.Date and cut.POSIXt problem
Roger D. Peng