8.3 Introductory Comments

Immediately following the gravitylab header, we see a lengthy comment block:

It starts with the name of the file, a brief summary with a reference to the literature, followed by a detailed description of how to use the code. For a typical user, this is all the information needed. As long as the user combines nbody_sh1 with other tools from gravitylab, there is even no need to understand the external data format, in which the $N$-body snapshots are written to and read from files. For those users interested in such details, as well as in the internal format in which the data are stored during the execution of the code, the comment block contains format information near the end. The last few lines list the history and version numbers of the code.