"could not find function" after import

Duncan

I have a related question.

I need one function from R.utils.  But R.utils depends on R.oo and  R.methodsS3.
so I made R.util an import and then used importFrom() in the namespace.

The package passed the  "check".  However when it came to use the function
it had not been loaded? do I need to add the upstream packages that
R.util  depends
upon?  also in the code do I need a library or require?

A bit confused

Steve

On Mon, Sep 19, 2011 at 5:09 PM, Duncan Murdoch
<murdoch.duncan at gmail.com>  wrote:

 On 11-09-19 4:48 PM, Stephanie M. Gogarten wrote:

 I am trying to build a package (GWASTools, submitted to Bioconductor)
 that uses the "sandwich" package.  I have references to "sandwich" in
 DESCRIPTION:
 Imports: methods, DBI, RSQLite, sandwich, survival, DNAcopy

 and NAMESPACE:
 import(sandwich)

 In the code itself is a call to vcovHC:
 Vhat<- vcovHC(mod, type="HC0")

 I have sandwich version 2.2-7 installed.

 When I run R CMD check on my package, I get the following error during
 checking of examples:
 * using R Under development (unstable) (2011-08-29 r56828)
 * using platform: x86_64-apple-darwin9.8.0 (64-bit)
 ...
 * checking examples ... ERROR
 ...
 Error in estfun.glm(x) : could not find function "is.zoo"
 Calls: assocTestRegression ... meatHC ->    rowMeans ->    is.data.frame ->
 estfun ->    estfun.glm

 I import sandwich, sandwich depends on zoo, but a function in zoo cannot
 be found during execution.

 I tried to get around this by explicitly including a "require" statement
 in assocTestRegression:
 require(sandwich)

 The example now runs, but I have a warning in R CMD check:
 * checking for unstated dependencies in R code ... WARNING
 ?library? or ?require? call not declared from: ?sandwich?

 I am not sure why this is a problem, as there is a "require" statement
 (for a different package) in another function which does not cause any
 warnings.

 Can anyone advise on how to get my package to successfully pass R CMD
 check?

 If you said that your package Depends on sandwich, you'd probably pass
 checks, but this is arguably a bug in the sandwich package.

 The problem is that since you only import sandwich, it never gets attached.
   So it never attaches its dependency zoo.   It should import zoo (or import
 the functions in zoo that it uses) to work properly the way you are calling
 it.

 You can see the same error as follows:

 1.  Install sandwich, but don't attach it or zoo.

 2.  Run

 example(glm)

 to create the "glm" object glm.D93.

 Try to call

 sandwich::estfun(glm.D93)

 You'll get the same error as before because is.zoo() will not be loaded.

 It's also arguably a design flaw in R.  For testing sandwich, zoo would
 generally end up being attached, because the testing of sandwich would
 attach it.  However, examples like the one above are never tested.

 Duncan Murdoch