[R] What is the most efficient practice to develop an R package?

[Peng Yu]

On Mon, Oct 26, 2009 at 11:22 AM, Dirk Eddelbuettel <edd at debian.org> wrote:
>
> On 26 October 2009 at 07:57, Martin Morgan wrote:
> | Peng Yu wrote:
> | > I am reading Section 5 and 6 of
> | > http://cran.r-project.org/doc/contrib/Leisch-CreatingPackages.pdf
> | >
> | > It seems that I have to do the following two steps in order to make an
> | > R package. But when I am testing these package, these two steps will
> | > run many times, which may take a lot of time. So when I still develop
> | > the package, shall I always source('linmod.R') to test it. Once the
> | > code in linmod.R is finalized, then I run the following two steps?
> | >
> | > I'm wondering what people usually do when developing packages.
> | >
> | >
> | > 1. Run the following command in R to create the package
> | > package.skeleton(name="linmod", code_files="linmod.R")
> |
> | Do this once, to get a skeleton. Then edit the R source etc in the
> | created package.
> |
> | > 2. Run the following command in shell to install
> | > R CMD INSTALL -l /path/to/library linmod
> |
> | see R CMD INSTALL --help and use options that minimize the amount of
> | non-essential work, e.g., no vignettes or documentation until that is
> | the focus of your development, or --libs-only if you are working on C
> | code. Use --clean to avoid stale package components. Develop individual
> | functions interactively, but write a script
> |
> |   library(MyPackage)
> |   someFunction()
> |
> | so that R -f myscript.R allows you to easily load your package and test
> | specific functionality in a clean R session.
>
> With littler you can do without the one-off script as
>
>     $ r -lMyPackage -e'print(someFunction())'
>
> runs both commands you would have put into script.  Hence, I often do
> something like
>
>     $ R CMD INSTALL MyPackage/ && r -lMyPackage -e'print(someFunction())'

What does the small case 'r' do?