[R] explicit coercion warnings as.numeric Versus as.logical

Bert Gunter bgunter.4567 at gmail.com
Mon Nov 21 16:57:18 CET 2016


Not an answer, but note that your vectors are all first (silently)
coerced to character, as vectors must be all of one type.

I would hazard a guess that the answer is: it's simply an arbitrary
inconsistency (different folks wrote the functions at different
times). Note that AFAICS, the difference has no effect on the behavior
of the two functions, i.e. the behavior is consistent, which is what
counts. However, I of course defer to real experts.

-- Bert
Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Mon, Nov 21, 2016 at 1:52 AM, Ramnik Bansal <ramnik.bansal at gmail.com> wrote:
> Hi,
>
> I am trying to understand under which specific conditions does explicit
> coercion produce warnings.
>
>> as.numeric(c(1, F, "b"))
> [1]  1 NA NA
> Warning message:
> NAs introduced by coercion
>
>> as.logical(c(1, F, "b"))
> [1]    NA FALSE    NA
>
>
> In above examples, as.numeric produces warning but as.logical does not.
> What is the reason behind this different behaviour. Ideally as.logical
> should also have produced the warning message like as.numeric.
>
> Thanks in advance.
> Ramnik
>
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>
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