On Feb 21, 2010, at 2:19 PM, Newbie19_02 wrote:
Hi everyone,
I have another fairly simple question. I want to take the earliest
of two
dates from these two date columns. I've tried converting the dates to
numbers and just get a vector full of NA's. I've also tried using
the chron
function to compare the two and have been unsuccessful. I then
tried to
use:temp.2 <- as.POSIXct(strptime(temp, '%d/%m/%Y')) where temp is
character
vector of one of the date columns this did not work either. I'm not
sure
what to do now.
date_1 date_2
2005-11-25 <NA>
2007-10-23 <NA>
<NA> 1999-12-13
2006-01-25 <NA>
2006-06-12 <NA>
2005-08-08 <NA>
2007-12-12 <NA>
2008-04-29 <NA>
2005-03-28 <NA>
2004-11-18 2000-11-02
2006-03-16 <NA>
2007-01-17 <NA>
We cannot tell from that output what data type you are working with.
You may not be working with Dates at all. You also have not offered
the code that is not working. If they are dates, then pmin should work
well.
> pmin(as.Date("2004-11-18"), as.Date("2000-11-02"))
[1] "2000-11-02"
Next time use dput to allow unambiguous communication. (The fact that
you are not using either dput or dump suggests you have not yet spent
enough effort at reading the Posting Guide.)
--
David
Thanks for your help,
Natalie
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and provide commented, minimal, self-contained, reproducible code.
