From hadley at rice.edu  Thu Feb  4 00:38:11 2010
From: hadley at rice.edu (Hadley Wickham)
Date: Wed, 3 Feb 2010 17:38:11 -0600
Subject: [Rd] Proposal unary - operator for factors
In-Reply-To: <77EB52C6DD32BA4D87471DCD70C8D7000275B14F@NA-PA-VBE03.na.tibco.com>
References: <f8e6ff051002031510m4dca3c8co8d69c3117e1deab4@mail.gmail.com> 
	<77EB52C6DD32BA4D87471DCD70C8D7000275B14F@NA-PA-VBE03.na.tibco.com>
Message-ID: <f8e6ff051002031538ub5c2892ya83806ad3fe025a0@mail.gmail.com>

> 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)

Hadley

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http://had.co.nz/



[Rd] Proposal unary - operator for factors
Hadley Wickham