From ripley at stats.ox.ac.uk  Wed Dec 23 11:23:21 2009
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Wed, 23 Dec 2009 10:23:21 +0000 (GMT)
Subject: [Rd] cut.POSIXt problem with breaks= "quarter" (PR#14162)
In-Reply-To: <20091221124509.A2AFC282EFFB@mail.pubhealth.ku.dk>
References: <20091221124509.A2AFC282EFFB@mail.pubhealth.ku.dk>
Message-ID: <alpine.LFD.2.00.0912231020030.8321@gannet.stats.ox.ac.uk>

What exactly is the purported bug here?  It seems to me that the cuts 
are correct and the behaiour is as documented, but that you were not 
expecting empty levels.  If that bothers you, use

cut(x, breaks= "quarter")[,drop=TRUE]


On Mon, 21 Dec 2009, shmunde at googlemail.com wrote:

> Full_Name: Qing Xia
> Version: 2.10.0
> OS: Windows XP
> Submission from: (NULL) (213.71.23.233)
>
>
> I find, when I use "cut" function to cut date-time objects based on breaks =
> "quarter", there exists a problem. It means, if the date-time has "JJJJ-MM-30"
> or "JJJJ-MM-31", then "cut" runs not correctly, it gives wrong levels. Detail
> can be found in the following R-Output:
>
> 1. correct Output levels, if there is no date-time "JJJJ-MM-30" or "JJJJ-MM-31"
>
>> x<- as.Date(c("2009-03-21","2009-03-24"))
>> cut(x, breaks= "quarter")
> [1] 2009-01-01 2009-01-01
> Levels: 2009-01-01
>
>
> 2. wrong Output levels, if there exists date-time "JJJJ-MM-30" or "JJJJ-MM-31"
>
>> x<- as.Date(c("2009-03-21","2009-03-30"))
>> cut(x, breaks= "quarter")
> [1] 2009-01-01 2009-01-01
> Levels: 2009-01-01 2009-04-01
>
>
>> x<- as.Date(c("2009-03-21","2009-03-31"))
>> cut(x, breaks= "quarter")
> [1] 2009-01-01 2009-01-01
> Levels: 2009-01-01 2009-04-01
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

-- 
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



[Rd] cut.POSIXt problem with breaks= "quarter" (PR#14162)
Prof Brian Ripley