Hi all,

I'd like to point out a pull request I just made, which fixes a number of fields that have been returning incorrect data. In particular, the definitions of the fields `velocity_spherical_theta`, `velocity_spherical_phi`, and `velocity_cylindrical_theta` have not been correct for at least three years, possibly longer - I haven't checked to see if they were ever correct.

Here's a pull request that implements a fix and adds some new tests:


While it's nice that we know there's an issue now and that it's fixed, this means that if someone was making a profile of the tangential velocity around a star, or the poloidal magnetic field in a disk simulation, or a circular velocity in a galaxy simulation, yt may have silently returned incorrect results.

I'm raising this issue here because it feels like it might be a big deal. Should this concern be raised more loudly to our users? I'm hesitant to do so, mostly out of sheepishness. Is this as big a deal as I'm making it out to be?