Command Line

Tracktable’s various rendering facilities have a lot of options. Python makes it easy for us to expose these as command-line options that can be passed to scripts. However, that just pushes the problem out one level: now the user has to remember the values for all of those options, or else write shell scripts that call Python scripts in order to keep track of what parameters were used where.

We introduce two facilities to help tame this morass:

1. Argument Groups: An argument group is a set of command-line arguments that all pertain to a single capability. For example, the argument group for trajectory assembly has entries for the maximum separation distance, maximum separation time and minimum length as described above in Assembling Points into Trajectories.

2. Response Files: A response file is a way to package up arbitrarily many command-line arguments in a file and pass them to a script all at once. It is independent of which script is being run. Since a response file is just text it is easy to place under version control. We provide a slightly modified version of the standard Python argparse module that includes support for response files containing comments and response files that load other response files.