On 30/01/2018 11:29 AM, Brian G. Peterson wrote:
On Tue, 2018-01-30 at 17:00 +0100, Suzen, Mehmet wrote:
Dear R developers,
I am wondering what are the best practices for developing an R
package. I am aware of Hadley Wickham's best practice
documentation/book (http://r-pkgs.had.co.nz/). I recall a couple of
years ago there were some tools for generating a package out of a
single file, such as using package.skeleton, but no auto-generated
documentation. Do you know a way to generate documentation and a
package out of single R source file, or from an environment?
Mehmet,
This list is for development of the R language itself and closely
related tools. There is a separate list, R-pkg-devel, for development
of packages.
Since you're here, I'll try to answer your question.
package.skeleton can create a package from all the R functions in a
specified environment. So if you load all the functions that you want
in your new package into your R environment, then call
package.skeleton, you'll have a starting point.
At that point, I would probably recommend moving to RStudio, and using
RStudio to generate markdown comments for roxygen for all your newly
created function files. Then you could finish off the documentation by
writing it in these roxygen skeletons or copying and pasting from
comments in your original code files.
I'd agree about moving to RStudio, but I think Roxygen is the wrong
approach for documentation. package.skeleton() will have done the boring
mechanical part of setting up your .Rd files; all you have to do is edit
some content into them. (Use prompt() to add a new file if you add a new
function later, don't run package.skeleton() again.)
This isn't the fashionable point of view, but I think it is easier to get
good documentation that way than using Roxygen. (It's easier to get bad
documentation using Roxygen, but who wants that?)
The reason I think this is that good documentation requires work and
thought. You need to think about the markup that will get your point
across, you need to think about putting together good examples, etc.
This is *harder* in Roxygen than if you are writing Rd files, because
Roxygen is a thin front end to produce Rd files from comments in your .R
files. To get good stuff in the help page, you need just as much work as
in writing the .Rd file directly, but then you need to add another layer on
top to put in in a comment. Most people don't bother.
I don't know any packages with what I'd consider to be good documentation
that use Roxygen. It's just too easy to write minimal documentation that
passes checks, so Roxygen users don't keep refining it.
(There are plenty of examples of packages that write bad documentation
directly to .Rd as well. I just don't know of examples of packages with
good documentation that use Roxygen.)
Based on my criticism last week of git and Github, I expect to be called a
grumpy old man for holding this point of view. I'd actually like to be
proven wrong. So to anyone who disagrees with me: rather than just
calling me names, how about some examples of Roxygen-using packages that
have good help pages with good explanations, and good examples in them?
Back to Mehmet's question: I think Hadley's book is pretty good, and I'd
recommend most of it, just not the Roxygen part.
Duncan Murdoch