Some issues seem to have cropped up in the disk data container in yt-3.0.  I made a disk object in a periodic simulation in the following way:

http://paste.yt-project.org/show/5021/

I then made a project of the "cylindrical_z" field, which yielded the following:

For reference, the domain is ~45 Mpc in length on a side, so the sphere should be just the object at the bottom, extending a little less than halfway up.  I don't know what that top part is about.  My guess is that it's an issue with periodicity.

Secondly, I made a similar projection of the "cylindrical_r" field, which gave this:

As you can see, it is not symmetric as one would expect.  For reference, this is what I get from yt-2.x:

This is what I would expect.

Does anyone have any insight on this?

Britton