2013/7/30 j s <j.s4403 at gmail.com>: > Thanks for your response. What is the format for characteristic? The example > online, bgmesh.pos, has 3 values. What do they mean? I don't know. I didn't really look into it at all; there's no need to. The previously outlined procedure accomplishes the stated goal and I left it at that, regarding the .pos format as an intermediate black box.