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

[Tomas Kalibera]

Thanks, fixed in 72737 (R-devel).

Best
Tomas

On 05/23/2017 06:32 PM, Evan Cortens wrote:
> Yes, what Joris posts about is exactly what I noted in my March 9th post to
> R-devel. The behaviour is sort of documented, but not in the clearest
> manner (in my opinion). Like I say, my ultimate conclusion was that the
> silent coercion of numerics to integers by sprintf() was a handy
> convenience, but not one that should be relied about to always work
> predictably.
>
> On Tue, May 23, 2017 at 10:02 AM, Michael Chirico <michaelchirico4 at gmail.com
>> wrote:
>> https://github.com/Rdatatable/data.table/issues/2171
>>
>> The fix was easy, it's just surprising to see the behavior change almost
>> on a whim. Just wanted to point it out in case this is unknown behavior,
>> but Evan seems to have found this as well.
>>
>> On Tue, May 23, 2017 at 12:00 PM, Michael Chirico <
>> michaelchirico4 at gmail.com> wrote:
>>
>>> 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
>>>> -------------------------------
>>>> Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php
>>>>
>>>
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