In Wintrack, the arena itself, the goal, and all other objects (e.g.
reference annuli, quadrants, release points) which make up your experimental
setup are treated as fields. Fields can be displayed in case windows
along with the animal's path and can be referred to during data analysis.
For each predefined type of arena, there is a standard set of fields
which can be specified in a simple dialog offered by the Arena Properties
command. As an alternative, the command also reads custom setup files
which can define fields in a much more flexible way. In these files,
the name, shape, size, position, graphical appearance, and other properties
of each field are defined by a corresponding Field statement.