[R] R CMD check: problems possibly from mapply?

[Ulrike Grömping]

Dear expeRts,

I am trying to wrap up a package "utilities" (for my internal use). After 
adding a function datNAtreat that uses mapply, R CMD check gives WARNINGs 
for "S3 generic/method consistency", "checking replacement functions" 
and "checking foreign function calls", all of which are accompanied by the 
following error message:

Error in .try_quietly ....: Error: unable to load R code in 
package 'utilities' 
Execution halted

Additionally, I get an ERROR for missing documentation entries (which I don't 
understand, because this function like all others is documented).

R CMD check works without problems when omitting this function. The function 
itself also works when running the code outside the package. I have now 
stripped it down (omitted error controls etc., it still works), and can only 
guess that the R CMD check problems have to do with mapply (with which I am 
not all that familiar).

I include the code (not reproducible) in case someone has an idea what I can 
do to make this function packageable. (The function as.factora is defined 
elsewhere in the package and takes the arguments x (a column of a data 
frame), na.level and na.show (a logical).):

##########################################################
datNAtreat <- function(x, na.levels=NULL, na.show=FALSE) {
    if (!is.data.frame(x)) x <- as.data.frame(x)
    names <- colnames(x)
    if (is.null(names)) names <- paste("x",1:ncol(x),sep="")
    x <- as.data.frame(mapply(as.factora, x, na.level=na.levels, 
             MoreArgs=list(na.show = na.show), SIMPLIFY=FALSE))
    colnames(x) <- names
    return(x)
}
############################################################

Any suggestions are appreciated, as I have no idea where else to look.

With kind regards, Ulrike