0. Preface
In the previous volume, a general framework has been sketched for a
command line options parser, and a specific Ruby implementation has
been provided. In the current volume, that implementation is used
to provide a user interface for N-body experiments. Driven by user
demand, a number of extensions are added to the basic program, to make
it even more useful as a practical interface between the user and an
N-body code.
0.1. Acknowledgments
We thank xxx, xxx, and xxx for their comments on the
manuscript.
Piet Hut and Jun Makino