From danielho at stud.ntnu.no  Tue Nov 11 20:35:48 2008
From: danielho at stud.ntnu.no (=?ISO-8859-1?Q?Daniel_H=F8yer_Iversen?=)
Date: Tue, 11 Nov 2008 20:35:48 +0100
Subject: [Rd] is.matrix
In-Reply-To: <f8e6ff050811111121u62cc1329s605ca0dcd521dfb2@mail.gmail.com>
References: <d8858f220811111020j233d4d98j502c0079ace644e7@mail.gmail.com>
	<4919D240.4040904@acm.org>
	<f8e6ff050811111121u62cc1329s605ca0dcd521dfb2@mail.gmail.com>
Message-ID: <d8858f220811111135s644fb759nc150c4094ca11398@mail.gmail.com>

> That's confusing!  In what situations is x a matrix but does not have
> a dim attribute?

That was my point. I don't find it logical that
is.matrix(a) gives FALSE but
is.matrix(t( t(a) )) gives TRUE.

I also think it would be more logical that
a=c(1,1,2)
dim(a) gives 3 1 instead of NULL,



Daniel



On Tue, Nov 11, 2008 at 8:21 PM, hadley wickham <h.wickham at gmail.com> wrote:
>> |  is.matrix| returns |TRUE| if |x| is a matrix and has a |dim <dim.html>|
>> attribute of length 2) and |FALSE| otherwise
>
> That's confusing!  In what situations is x a matrix but does not have
> a dim attribute?
>
> Hadley
>
> --
> http://had.co.nz/
>
>



[Rd] is.matrix
=?ISO-8859-1?Q?Daniel_H=F8yer_Iversen?=