[Rd] Bug in the "reformulate" function in stats package

[Ben Bolker]

  I suspect that the issue is addressed (obliquely) in the examples,
which shows that variables with spaces in them (or otherwise
'non-syntactic', i.e. not satisfying the constraints of legal R symbols)
can be handled by protecting them with backticks  (``)

 ## using non-syntactic names:
     reformulate(c("`P/E`", "`% Growth`"), response = as.name("+-"))

It seems to me there could be room for a *documentation* patch (stating
explicitly that if termlabels has length > 1 its elements are
concatenated with "+", and explicitly stating that non-syntactic names
must be protected with back-ticks).  (There is a little bit of obscurity
in the fact that the elements of termlabels don't have to be
syntactically valid names: many will be included in formulas if they can
be interpreted as *parseable* expressions, e.g. reformulate("x<2"))

  I would be happy to give it a shot if the consensus is that it would
be worthwhile.

   One workaround to the OP's problem is below (may be worth including
as an example in docs)

> z <- c("a variable","another variable")
> reformulate(z)
Error in parse(text = termtext, keep.source = FALSE) :
  <text>:1:6: unexpected symbol
1:  ~ a variable
         ^
> reformulate(sprintf("`%s`",z))
~`a variable` + `another variable`




On 2019-03-29 11:54 a.m., J C Nash wrote:
> The main thing is to post the "small reproducible example".
> 
> My (rather long term experience) can be written
> 
>   if (exists("reproducible example") ) {
>      DeveloperFixHappens()
>   } else {
>      NULL
>   }
> 
> JN
> 
> On 2019-03-29 11:38 a.m., Saren Tasciyan wrote:
>> Well, first I can't sign in bugzilla myself, that is why I wrote here first. Also, I don't know if I have the time at
>> the moment to provide tests, multiple examples or more. If that is not ok or welcomed, that is fine, I can come back,
>> whenever I have more time to properly report the bug.
>>
>> I didn't find the existing bug report, sorry for that.
>>
>> Yes, it is related. My problem was that I have column names with spaces and current solution doesn't solve it. I have a
>> solution, which works for me and maybe also for others.
>>
>> Either, someone can register me to bugzilla or I can post it here, which could give some direction to developers. I
>> don't mind whichever is preferred here.
>>
>> Best,
>>
>> Saren
>>
>>
>> On 29.03.19 09:29, Martin Maechler wrote:
>>>>>>>> Saren Tasciyan
>>>>>>>>      on Thu, 28 Mar 2019 17:02:10 +0100 writes:
>>>      > Hi,
>>>      > I have found a bug in reformulate function and have a solution for it. I
>>>      > was wondering, where I can submit it?
>>>
>>>      > Best,
>>>      > Saren
>>>
>>>
>>> Well, you could have given a small reproducible example
>>> depicting the bug, notably when posting here:
>>> Just a prose text with no R code or other technical content is
>>> almost always not really appropriate fo the R-devel mailing list.
>>>
>>> Further, in such a case you should google a bit and hopefully
>>> have found
>>>         https://www.r-project.org/bugs.html
>>>
>>> which also mention reproducibility (and many more useful things).
>>>
>>> Then it also tells you about R's bug repository, also called
>>> "R's bugzilla" at https://bugs.r-project.org/
>>>
>>> and if you are diligent (but here, I'd say bugzilla is
>>> (configured?) far from ideal), you'd also find bug PR#17359
>>>
>>>     https://bugs.r-project.org/bugzilla/show_bug.cgi?id=17359
>>>
>>> which was reported already on Nov 2017 .. and only fixed
>>> yesterday (in the "cleanup old bugs" process that happens
>>> often before the big new spring release of R).
>>>
>>> So is your bug the same as that one?
>>>
>>> Martin
>>>
>>>      > --
>>>      > Saren Tasciyan
>>>      > /PhD Student / Sixt Group/
>>>      > Institute of Science and Technology Austria
>>>      > Am Campus 1
>>>      > 3400 Klosterneuburg, Austria
>>>
>>>      > ______________________________________________
>>>      > R-devel using r-project.org mailing list
>>>      > https://stat.ethz.ch/mailman/listinfo/r-devel
>>>
>>> ______________________________________________
>>> R-devel using r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
> 
> ______________________________________________
> R-devel using r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>