From J.C.Rougier@durham.ac.uk  Tue Aug 14 09:09:18 2001
From: J.C.Rougier@durham.ac.uk (J.C.Rougier@durham.ac.uk)
Date: Tue, 14 Aug 2001 10:09:18 +0200 (MET DST)
Subject: [Rd] Inconsistent behaviour of is.vector? (PR#1052)
Message-ID: <200108140809.KAA19242@pubhealth.ku.dk>

Hi everyone,

I have noticed that is.vector returns FALSE if I attach
attributes:

> x <- c(a = 1, b = 2)
> attributes(x)
$names
[1] "a" "b"

> is.vector(x)
[1] TRUE
> attr(x, "fred") <- "happy"
> attributes(x)
$names
[1] "a" "b"

$fred
[1] "happy"

> is.vector(x)
[1] FALSE

This seems inconsistent to me, as "names" is itself an attribute
yet this does negate is.vector.  As the original x is clearly a
vector, albeit one with names, wouldn't it be consistent to allow
any attributes?  This appears to be the case for is.matrix ...

> x <- matrix(1:4, 2, 2)
> is.matrix(x)
[1] TRUE
> attributes(x)
$dim
[1] 2 2
> attr(x, "fred") <- "happy"
> x
     [,1] [,2]
[1,]    1    3
[2,]    2    4
attr(,"fred")
[1] "happy"
> is.matrix(x)
[1] TRUE

Cheers, Jonathan.

--please do not edit the information below--

Version:
 platform = i686-pc-linux-gnu
 arch = i686
 os = linux-gnu
 system = i686, linux-gnu
 status = Patched
 major = 1
 minor = 3.0
 year = 2001
 month = 06
 day = 27
 language = R

Search Path:
 .GlobalEnv, Autoloads, package:base

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[Rd] Inconsistent behaviour of is.vector? (PR#1052)
J.C.Rougier@durham.ac.uk