From @g|@nner|n| @end|ng |rom gm@||@com  Sat Sep 23 21:41:16 2023
From: @g|@nner|n| @end|ng |rom gm@||@com (Simone Giannerini)
Date: Sat, 23 Sep 2023 21:41:16 +0200
Subject: [Rd] NROW and NCOL on NULL
In-Reply-To: <936870db-2e16-4b8b-878b-c2dde317319c@gmail.com>
References: <CANcXGizv3sD3kiE__EUkuaESn44mvtQMrtpO_k=FjUwFQDGnVQ@mail.gmail.com>
 <936870db-2e16-4b8b-878b-c2dde317319c@gmail.com>
Message-ID: <CANcXGiz9g6mAsnNd3=Uc9iQ5xvE8Mg2ws5fbsEFYVXB_HL=Sog@mail.gmail.com>

I know it's documented and I know there are other ways to guard
against this behaviour, once you know about this.
The point is whether it might be worth it to make NCOL and NROW return
the same value on NULL and make R more consistent/intuitive and
possibly less error prone.

Regards,

Simone

On Sat, Sep 23, 2023 at 7:50?PM Duncan Murdoch <murdoch.duncan at gmail.com> wrote:
>
> It's been documented for a long time that NCOL(NULL) is 1.  What
> particular problems did you have in mind?  There might be other ways to
> guard against them.
>
> Duncan Murdoch
>
> On 23/09/2023 1:43 p.m., Simone Giannerini wrote:
> > Dear list,
> >
> > I do not know what would be the 'correct' answer to the following but
> > I think that they should return the same value to avoid potential
> > problems and hard to debug errors.
> >
> > Regards,
> >
> > Simone
> > ---------------------------------------
> >
> >> NCOL(NULL)
> > [1] 1
> >
> >> NROW(NULL)
> > [1] 0
> >
> >> sessionInfo()
> > R version 4.3.1 RC (2023-06-08 r84523 ucrt)
> > Platform: x86_64-w64-mingw32/x64 (64-bit)
> > Running under: Windows 11 x64 (build 22621)
> >
> > Matrix products: default
> >
> >
> > locale:
> > [1] LC_COLLATE=Italian_Italy.utf8  LC_CTYPE=Italian_Italy.utf8
> > [3] LC_MONETARY=Italian_Italy.utf8 LC_NUMERIC=C
> > [5] LC_TIME=Italian_Italy.utf8
> >
> > time zone: Europe/Rome
> > tzcode source: internal
> >
> > attached base packages:
> > [1] stats     graphics  grDevices utils     datasets  methods   base
> >
> > loaded via a namespace (and not attached):
> > [1] compiler_4.3.1
> >
>


-- 
___________________________________________________

Simone Giannerini
Dipartimento di Scienze Statistiche "Paolo Fortunati"
Universita' di Bologna
Via delle belle arti 41 - 40126  Bologna,  ITALY
Tel: +39 051 2098262  Fax: +39 051 232153
https://simonegiannerini.net/



[Rd] NROW and NCOL on NULL
Simone Giannerini