Issue I549 [resolved,sds] SDS cylindrical symmetry velocity arrays broken. In collision_sds.lua prior to 20100427, this line local vel_coords should instead be local vel_coords = (velx_defs or vely_defs or velz_defs) and "abs_gu" or nil That ensures that arrays loaded via load_array have the proper velocity coordinate system. The older PRG version of SDS is not affected by this. reported by AEGatNSCL-20100426: http://simion.com/discuss/topic/964-sds-in-lua-cylindrical-symmetry-broken Resolved in 20100427 version of collision_sds example