1) Quick version

1.1) Building

make

1.2) Installing

sudo make install

2) Detailed version

2.1) Building

Roxygen (http://roxygen.org/) is used to build the documentation. The
makefile runs
$ R CMD roxygen -d .
to build the documentation. This writes files into ./inst/, ./man/,
./DESCRIPTION/ and possible others I have forgotten.

After Roxygen is run, the directory should contain a valid R package,
which may be built using
$ R CMD build .
which is what the makefile does. This will produce a .tar.gz file in the
./build/ directory.

2.2) Installing

The .tar.gz can be installed with
$ R CMD INSTALL build/insidefunctor_0.1.tar.gz
which is what the Makefile will run.