Cactus Code Thorn RotatingSymmetry180 Author(s) : Erik Schnetter Maintainer(s): Erik Schnetter Licence : GPL -------------------------------------------------------------------------- 1. Purpose Provide a 180 degree rotational symmetry boundary condition. This is the kind of symmetry that exists e.g. in a binary black hole evolution when the two black holes are identical. The same setup also admits an additional bitant symmetry. Currently the symmetry is fixed to be located at the lower x boundary, so that there is a rotation about the z axis. The coordinate thorn does not know about this symmetry. You will have to set up the domain such that you have an upper bitant in the x direction. This symmetry boundary condition can be mixed with arbitrary symmetry conditions in the z direction, e.g. bitant or periodicity.