I have been working with Jia-Hung on looking at vorticity in his GAMER simulations. He has supplied me with a dataset where the minimum vorticity (by prescription) should be at the center.
After a lot of back and forth with him and with Jeff Oishi, I determined that what looks to be happening is that unless I set the number of ghost zones to 2 (instead of 1) there is a systematic offset.
Can anybody think why this might be?
I'm working on making this into a unit test to check its behavior in 3.0.