So, am I correct that each datum is either of the form "mm/dd/yy" or
of the form "dd/mm/yyyy"? If that is correct, then the following
should work, and takes care of converting 99 to 1999 instead of 2099:
dates <- c("06/15/07","04/09/99","20/03/2008")
short <- grep("\\d\\d/\\d\\d/\\d\\d$", dates, perl=TRUE)
dates[short] <- format(strptime(dates[short], format="%m/%d/%y"),
format="%d/%m/%Y")
Or Henrique's suggestion, slightly modified:
strptime(dates, ifelse(nchar(dates) == 8, '%m/%d/%y', '%d/%m/%Y'))
Haris Skiadas
Department of Mathematics and Computer Science
Hanover College
On Sep 10, 2008, at 7:40 AM, Megh Dal wrote:
It is a mixture of both. The data is so notorious excel cant format
properly. Therefore I thought whether R can do something otherwise
I have to do manually.
--- On Tue, 9/9/08, Dr Eberhard W Lisse <[EMAIL PROTECTED]> wrote:
From: Dr Eberhard W Lisse <[EMAIL PROTECTED]>
Subject: Re: [R] Compiling date
To: "David Scott" <[EMAIL PROTECTED]>
Cc: "Dr Eberhard W Lisse" <[EMAIL PROTECTED]>, "Megh Dal"
<[EMAIL PROTECTED]>, [EMAIL PROTECTED]
Date: Tuesday, September 9, 2008, 11:37 PM
Is this Month-Day or Day-Month or a mixture of both?
I still think using the Format -> Cell -> Date will
work
much better...
el
On 09 Sep 2008, at 11:21 , David Scott wrote:
On Mon, 8 Sep 2008, Megh Dal wrote:
Hi,
I have following kind of dataset (all are dates)
in my Excel sheet.
09/08/08
09/05/08
09/04/08
09/02/08
09/01/08
29/08/2008
28/08/2008
27/08/2008
26/08/2008
25/08/2008
22/08/2008
21/08/2008
20/08/2008
18/08/2008
14/08/2008
13/08/2008
08/12/08
08/11/08
08/08/08
08/07/08
However I want to use R to compile those data to
make all dates in
same format. Can anyone please tell me any
automated way for doing
that?
Well you have to read them in as character first. Then
use sub to
make the two digit years into four digits. The
following could
probably be improved by a regular expression whiz, but
works:
strngs <-
c("06/05/08","23/11/2008")
sub("([0-9][0-9]/[0-9][0-9]/)([0-9][0-9]$)","\\120\\2",strngs)
[1] "06/05/2008" "23/11/2008"
David Scott
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