Ari B. Friedman Ari B. Friedman - 3 months ago 12
R Question

What to do with imperfect-but-useful functions?

I could equally have titled this question, "Is it good enough for CRAN?"

I have a collection of functions that I've built up for specific tasks. Some of these are convenience functions:

# Returns odds/evens from a vector
odds=function(vec) {
stopifnot(class(vec)=="integer")
ret = vec[fpart(vec/2)!=0]
ret
}
evens=function(vec) {
stopifnot(class(vec)=="integer")
ret = vec[fpart(vec/2)==0]
ret
}


Some are minor additions that have proven useful in answering common SO question:

# Shift a vector over by n spots
# wrap adds the entry at the beginning to the end
# pad does nothing unless wrap is false, in which case it specifies whether to pad with NAs
shift <- function(vec,n=1,wrap=TRUE,pad=FALSE) {
if(length(vec)<abs(n)) {
#stop("Length of vector must be greater than the magnitude of n \n")
}
if(n==0) {
return(vec)
} else if(length(vec)==n) {
# return empty
length(vec) <- 0
return(vec)
} else if(n>0) {
returnvec <- vec[seq(n+1,length(vec) )]
if(wrap) {
returnvec <- c(returnvec,vec[seq(n)])
} else if(pad) {
returnvec <- c(returnvec,rep(NA,n))
}
} else if(n<0) {
returnvec <- vec[seq(1,length(vec)-abs(n))]
if(wrap) {
returnvec <- c( vec[seq(length(vec)-abs(n)+1,length(vec))], returnvec )
} else if(pad) {
returnvec <- c( rep(NA,abs(n)), returnvec )
}

}
return(returnvec)
}


The most important are extensions to existing classes that can't be found anywhere else (e.g. a CDF panel function for lattice plots, various xtable and LaTeX output functions, classes for handling and converting between geospatial object types and performing various GIS-like operations such as overlays).

I would like to make these available somewhere on the internet in R-ized form (e.g. posting them on a blog as plain text functions is not what I'm looking for), so that maintenance is easier and so that I and others can access them from any computer that I go to. The logical thing to do is to make a package out of them and post them to CRAN--and indeed I already have them packaged up. But is this collection of functions suitable for a CRAN package?

I have two main concerns:


  1. The functions don't seem to have any coherent overlay. It's just a
    collection of functions that do lots of different things.

  2. My code isn't always the prettiest. I've tried to clean it up as I
    learned better coding practices, but producing R Core-worthy beautiful
    code is not in the cards.



The CRAN webpage is surprisingly bereft of guidelines on posting. Should I post to CRAN, given that some people will find it useful but that it will in some sense forever lock R into having some pretty basic function names taken up? Or is there another place I can use an install.packages-like command to install from? Note I'd rather avoid posting the package to a webpage and having people have to memorize the URL to install the package (not least for version control issues).

Answer

Most packages should be collections of related functions with an obvious purpose, so a useful thing to do would be to try and group what you have together, and see if you can classify them. Several smaller packages are better than one huge incoherent package.

That said, there are some packages that are collections of miscellaneous utility functions, most notably Hmisc and gregmisc, so it is okay to do that sort of thing. If you just have a few functions like that, it might be worth contacting the author of some of the misc packages and seeing if they'll let you include your code in their package.

As for writing pretty code, the most important thing you can do is to use a style guide.

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