Inflexibility in Bp direction causes issues with drifts #204
Description
Hypnotoad currently requires the poloidal magnetic field to point in in the clockwise direction (so that the grid starts at y=0, lower inner target for lower single-null, or outer upper for upper single-null). @johnomotani has suggested a potential fix:
'John Omotani: The problem is that hypnotoad assumes that the poloidal field always goes clockwise, so that the grid starts (y=0) at the lower-inner target (or upper-outer for an upper-single-null) and goes around to the lower-outer (upper-inner) target. I think it should be fairly straightforward to work around this - in cases/tokamak.py check if Bp is clockwise or anticlockwise, and if anticlockwise build the grid in the opposite direction (lower-outer -> lower-inner). It would probably be more work to test/verify than it would be to implement... although maybe it is more complicated to get right - see the open issue #56 here'
The work around currently is to use the reverse_current option in hypnotoad, but this will impact drifts and should be adressed.