Time in guiding center

[Beforerr]

What does xu in guiding_center represent for? Because in example we have gc_x0 = gc(stateinit) then xu[end] would be uz not t

function guiding_center(xu, param::FullTPTuple)
   q, m, _, B_field = param
   t = xu[end]
...
end

[henry2004y]

In guiding_center, I remember xu is supposed to be a 7-element vector (x, y, z, vx, vy, vz, t). However, in the current implementation the time information is not used at all, so a 6-element vector (x, y, z, vx, vy, vz) also works, but the last element xu[end] actually points to vz as you mentioned. This is indeed wrong.