[R] ncol() vs. length() on data.frames

[Ivan Calandra]

That's exactly why I was asking if it really is equivalent and if there
are issues using one function or the other

--
Dr. Ivan Calandra
TraCEr, laboratory for Traceology and Controlled Experiments
MONREPOS Archaeological Research Centre and
Museum for Human Behavioural Evolution
Schloss Monrepos
56567 Neuwied, Germany
+49 (0) 2631 9772-243
https://www.researchgate.net/profile/Ivan_Calandra

On 31/03/2020 15:39, Eric Berger wrote:
> Yes it does because length(list) gives you the number of elements of
> the list. And in the case of a data frame object that is the number of
> columns, or ncol().
>
> On Tue, Mar 31, 2020 at 4:37 PM Ivan Calandra <calandra using rgzm.de
> <mailto:calandra using rgzm.de>> wrote:
>
>     Thanks Eric,
>
>     I know that, but that doesn't really answer my question, does it?
>
>     Ivan
>
>     --
>     Dr. Ivan Calandra
>     TraCEr, laboratory for Traceology and Controlled Experiments
>     MONREPOS Archaeological Research Centre and
>     Museum for Human Behavioural Evolution
>     Schloss Monrepos
>     56567 Neuwied, Germany
>     +49 (0) 2631 9772-243
>     https://www.researchgate.net/profile/Ivan_Calandra
>
>     On 31/03/2020 15:26, Eric Berger wrote:
>     > A data frame is a special case of a list. It is a list of its
>     columns.
>     >
>     > > is.list( your_data_frame )
>     >
>     > # TRUE
>     >
>     >
>     > On Tue, Mar 31, 2020 at 4:04 PM Ivan Calandra <calandra using rgzm.de
>     <mailto:calandra using rgzm.de>
>     > <mailto:calandra using rgzm.de <mailto:calandra using rgzm.de>>> wrote:
>     >
>     >     Dear useRs,
>     >
>     >     I have a very simple question:
>     >     On a simple data.frame (i.e. each element is a vector),
>     ncol() and
>     >     length() will give the same result.
>     >
>     >     Are they just equivalent on such objects, or are they
>     differences in
>     >     some cases?
>     >     Is one of them to be preferred for whatever reason?
>     >
>     >     Thanks you,
>     >     Ivan
>     >
>     >     --
>     >     Dr. Ivan Calandra
>     >     TraCEr, laboratory for Traceology and Controlled Experiments
>     >     MONREPOS Archaeological Research Centre and
>     >     Museum for Human Behavioural Evolution
>     >     Schloss Monrepos
>     >     56567 Neuwied, Germany
>     >     +49 (0) 2631 9772-243
>     >     https://www.researchgate.net/profile/Ivan_Calandra
>     >
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