[Rd] Inconsistency in handling of numeric input with %d by sprintf

[Michael Chirico]

Astute observation. And of course we should be passing integer when we use
%d. It's an edge case in how we printed ITime objects in data.table:


On Tue, May 23, 2017 at 11:53 AM, Joris Meys <jorismeys at gmail.com> wrote:

> I initially thought this is "documented behaviour". ?sprintf says:
>
> Numeric variables with __exactly integer__ values will be coerced to
> integer. (emphasis mine).
>
> Turns out this only works when the first value is numeric and not NA, as
> shown by the following example:
>
> > sprintf("%d", as.numeric(c(NA,1)))
> Error in sprintf("%d", as.numeric(c(NA, 1))) :
>   invalid format '%d'; use format %f, %e, %g or %a for numeric objects
> > sprintf("%d", as.numeric(c(1,NA)))
> [1] "1"  "NA"
>
> So the safest thing is indeed passing the right type, but the behaviour is
> indeed confusing. I checked this on both Windows and Debian, and on both
> systems I get the exact same response.
>
> Cheers
> Joris
>
> On Tue, May 23, 2017 at 4:53 PM, Evan Cortens <ecortens at mtroyal.ca> wrote:
>
>> Hi Michael,
>>
>> I posted something on this topic to R-devel several weeks ago, but never
>> got a response. My ultimate conclusion is that sprintf() isn't super
>> consistent in how it handles coercion: sometimes it'll coerce real to
>> integer without complaint, other times it won't. (My particular email had
>> to do with the vectors longer than 1 and their positioning vis-a-vis the
>> format string.) The safest thing is just to pass the right type. In this
>> case, sprintf('%d', as.integer(NA_real_)) works.
>>
>> Best,
>>
>> Evan
>>
>> On Fri, May 19, 2017 at 9:23 AM, Michael Chirico <
>> michaelchirico4 at gmail.com>
>> wrote:
>>
>> > Consider
>> >
>> > #as.numeric for emphasis
>> > sprintf('%d', as.numeric(1))
>> > # [1] "1"
>> >
>> > vs.
>> >
>> > sprintf('%d', NA_real_)
>> >
>> > >  Error in sprintf("%d", NA_real_) :
>> >
>> >    invalid format '%d'; use format %f, %e, %g or %a for numeric object
>> > >
>> >
>> > I understand the error is correct, but if it works for other numeric
>> input,
>> > why doesn't R just coerce NA_real_ to NA_integer_?
>> >
>> > Michael Chirico
>> >
>> >         [[alternative HTML version deleted]]
>> >
>> > ______________________________________________
>> > R-devel at r-project.org mailing list
>> > https://stat.ethz.ch/mailman/listinfo/r-devel
>> >
>>
>>
>>
>> --
>> Evan Cortens, PhD
>> Institutional Analyst - Office of Institutional Analysis
>> Mount Royal University
>> 403-440-6529
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>
>
>
> --
> Joris Meys
> Statistical consultant
>
> Ghent University
> Faculty of Bioscience Engineering
> Department of Mathematical Modelling, Statistics and Bio-Informatics
>
> tel :  +32 (0)9 264 61 79 <+32%209%20264%2061%2079>
> Joris.Meys at Ugent.be
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