[Rd] Testing for vectors

Rui Barradas ruipb@rr@d@@ @ending from @@po@pt
Sat Jul 7 22:47:40 CEST 2018



Às 21:32 de 07-07-2018, Hadley Wickham escreveu:
> On Sat, Jul 7, 2018 at 1:50 PM, Gabe Becker <becker.gabe using gene.com> wrote:
>> Hadley,
>>> I was thinking primarily of completing the set of is.matrix() and
>>> is.array(), or generally, how do you say: is `x` a 1d dimensional
>>> thing?
>> Can you clarify what you mean by dimensionality sense and specifically 1d
>> here?
> What do we call a vector that is not an array? (or matrix)
> What do we call an object that acts 1-dimensional? (i.e. has
> length(dim()) %in% c(0, 1)) ?
>> You can also have an n x 1 matrix, which technically has 2 dimensions but
>> conceptually is equivalent to a 1d array and/or a vector.
> Yes. You can also have array that's n x 1 x 1.

In which case it would be

(length(dim(.)) - sum(dim(.) == 1)) %in% c(0, 1)

Hope this helps,

Rui Barradas

>> Also, are you including lists in your conceptions of 1d vector here? I'm
>> with Duncan here, in that i'm having trouble understanding exactly what you
>> want to do without a bit more context.
> Isn't it standard terminology that a vector is the set of atomic vectors + list?
> Hadley

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