This directory is for constructing an optical layout for KAGRA. KAGRA_OptLayout.py is the main script. This script is not intended to run from a command line. Instead, you should open the file and run the sections one by one. It uses a python module called gtrace to do the job. Before running the script, you have to add the "modules" directory to the Python's module search path. To do so, add the full path to the "modules" directory to the environment variable $PYTHONPATH.