-----Original Message-----
From: h.wickham at gmail.com [mailto:h.wickham at gmail.com] On
Behalf Of Hadley Wickham
Sent: Wednesday, February 03, 2010 3:38 PM
To: William Dunlap
Cc: r-devel at r-project.org
Subject: Re: [Rd] Proposal unary - operator for factors
It wouldn't make sense in the context of
? vector[-factor]
True, but that doesn't work currently so you wouldn't lose anything.
However, it would make a certain class of problem that used to throw
errors become silent.
Wouldn't it be better to allow order's decreasing argument
to be a vector with one element per ... argument? ?That
would work for numbers, factors, dates, and anything
else. ?Currently order silently ignores decreasing[2] and
beyond.
The problem is you might want to do something like order(a, -b, c, -d)