[Rd] Including a single function from a package

[Ken Kelley]

Thank you both very much for your quick and helpful responses.

I added "Imports: MASS, gsl" to the DESCRIPTION file and that took care 
of loading in the desired functions just fine. I went back and took 
another look at the "Specifying imports and exports" section (section 
1.6.1) of the Writing R Extensions manual and I do not see anything 
about including an "Imports:" line in the DESCRIPTION file when 
including an "importFrom" in the NAMESPACE file. Perhaps including this 
information in a future update should be considered.

I was building the package on a machine that had a pre-release version 
of R 2.3.0 (from some time ago). After updating to the released version 
of 2.3, the warning about a "depreciated NULL environment" did not occur 
and the package built just fine.

Thanks again and have a good day,
Ken


Prof Brian Ripley wrote:
> On Fri, 5 May 2006, Ken Kelley wrote:
> 
>> Hello all.
>>
>> I'm building a package where I want to include a function from two
>> different packages. In particular, I want to include mvrnorm and
>> hyperg_2F1 from MASS and gsl, respectively (but the specific functions
>> do not matter). With what I've tried after reading the "Specifying
>> imports and exports" section from the "Writing R Extensions" manual, I
>> get an error: "Namespace dependencies not required."
> 
> 
> When do you get the error?
> 
>> My NAMESPACE file consists of the following:
>> importFrom(MASS, mvrnorm)
>> importFrom(gsl, hyperg_2F1)
>> exportPattern("^[^\\.]")
> 
> 
> Does your DESCRIPTION file contain
> 
> Imports: MASS gsl
> 
> ?
> 
>> A completely separate issue is that when running check, I get a warning
>> at the "checking S3 generic/method consistency" line that states:
>> "Warning: use of NULL environment is depreciated." I've looked at the
>> "Generic functions and methods" in the Writing R Extensions manual and
>> I'm still not sure what the "use of NULL environment is depreciated." I
>> suppose this is not a big deal, but it seems best not to have any 
>> warnings.
> 
> 
> It is a big deal: your code will fail in 2.4.0 and not be allowed on 
> CRAN now.  The message is probably not to do with that topic but to do 
> with loading your package.  So can you install and load the package 
> without any messages?
> 
>> I'm sure I'm just missing something simple on both of these issues. Any
>> insight would be appreciated. I'm building the package with Win. XP.
> 
> 

-- 
Ken Kelley, Ph.D.
Indiana University
Inquiry Methodology Program
201 North Rose Avenue, Room 4040
Bloomington, Indiana 47405
(P/F) 812-856-8330 / 812-856-8333
http://www.indiana.edu/~kenkel