R devel - Nov 2004 - data() in data/*.R files

Hi

I'm having difficulty making a package pass R CMD check.

I need to read in a dataset from another package,  modify it, and have the
modified object available in the first package. help(require) says:

      The source code for a package that requires one or more other
      packages should have a call to 'require', preferably near the
      beginning of the source, and of course before any code that uses
      functions, classes or methods from the other package.

and 200update.txt points out that the  data/*.R files must be self
sufficient, suggesting  "require(pkg, quietly=TRUE, save=FALSE)"
if needed.  My .R file  in the data subdirectory looks like this:


   require(calibrator, quietly=TRUE, save=FALSE)
   data(expert.estimates, package="calibrator")
   <paraphrase>
  expert.estimates.modified <- some.function(expert.estimates)
   </paraphrase>


  But if I do this, R CMD check says

Error in eval(expr, envir, enclos) : couldn't find function "data"
Execution halted
ERROR: installing package indices failed
  ERROR
Installation failed.

[the package passes R CMD check if I cut-and-paste a dput  and assign 
expert.estimates.modified
directly, and dispense with the data() statement].

How do I load a dataset from another package in a .R file, and use it?



-- 
Robin Hankin
Uncertainty Analyst
Southampton Oceanography Centre
SO14 3ZH
tel +44(0)23-8059-7743
initialDOTsurname@soc.soton.ac.uk (edit in obvious way; spam precaution)
	[[alternative HTML version deleted]]

Robin Hankin wrote:
> Hi
> 
> I'm having difficulty making a package pass R CMD check.
> 
> I need to read in a dataset from another package,  modify it, and have the
> modified object available in the first package. help(require) says:
> 
>       The source code for a package that requires one or more other
>       packages should have a call to 'require', preferably near the
>       beginning of the source, and of course before any code that uses
>       functions, classes or methods from the other package.
> 
> and 200update.txt points out that the  data/*.R files must be self
> sufficient, suggesting  "require(pkg, quietly=TRUE, save=FALSE)"
> if needed.  My .R file  in the data subdirectory looks like this:
> 
> 
>    require(calibrator, quietly=TRUE, save=FALSE)
>    data(expert.estimates, package="calibrator")
>    <paraphrase>
>   expert.estimates.modified <- some.function(expert.estimates)
>    </paraphrase>
> 
> 
>   But if I do this, R CMD check says
> 
> Error in eval(expr, envir, enclos) : couldn't find function
"data"
> Execution halted
> ERROR: installing package indices failed
>   ERROR
> Installation failed.
> 
> [the package passes R CMD check if I cut-and-paste a dput  and assign 
> expert.estimates.modified
> directly, and dispense with the data() statement].
> 
> How do I load a dataset from another package in a .R file, and use it?
You need to require(utils) (the package data() is in),
as well as a corresponsing entry in the DESCRIPTION file.
Also, for Windows, you may need to add the line
ZipData: no
to your DESCRIPTION file, but I am not sure about the latter (and 
haven't tested yet).

Uwe



> 
>