R devel - May 2017 - Inconsistency in handling of numeric input with %d by sprintf

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
Joris.Meys at Ugent.be
-------------------------------
Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php

	[[alternative HTML version deleted]]

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
>
	[[alternative HTML version deleted]]

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
>>
>
>
	[[alternative HTML version deleted]]