[R] issue with nzchar() ?

[Bert Gunter]

Liviu:

Well, as usual, to a certain extent this is arbitrary and the only
issue is whether it is documented correctly.

To me, NA (of whatever mode) means ""indeterminate" or "unknown," so
since "" is known and of length 0, I would have expected NA as a
return. But the point is, not what our particular tastes are ("You say
'tomayto', I say 'tomahto,' an old song goes), but what the docs say.
And in both cases, they tell you exactly what you'll get.

For nchar(): " an integer vector giving the sizes of each element,
currently always 2 for missing values (for NA)"

and for nzchar: "a logical vector of the same length as x, true if and
only if the element has non-zero length." (note the 'only if').

So I see no error or inconsistencies anywhere.

-- Bert

On Mon, Aug 6, 2012 at 7:53 AM, Liviu Andronic <landronimirc at gmail.com> wrote:
> On Mon, Aug 6, 2012 at 4:48 PM, Liviu Andronic <landronimirc at gmail.com> wrote:
>> string, something that I find strange. At best NA is the equivalent of
>> an empty string. In this sense, if you Hmisc::describe() the vector
>> you get, as I would expect, that in the context of character vectors
>> NA and '' values are considered together:
>>
>
> By the way, same question holds for nchar(): Should NA values be
> reported as 2-char strings, or as 0-char empty/missing values?
>> x <- c(letters, NA, '')
>> nchar(x)
>  [1] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 0
>
>
> Liviu
>
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-- 

Bert Gunter
Genentech Nonclinical Biostatistics

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