Summary

Currently,axis3d.Axis inherits fromaxis.XAxis which inherits fromaxis.Axis. This is a bit strange and possibly inconvenient. Especially if we think that the 3D stuff will make it into the main library at some stage.

Proposed fix

Renameaxis3d.Axis toAxis3D.

One will have to check it there is anything inXAxis that is actually needed and then consider how to proceed. (One may guess that anything needed inXAxis is so generic that it can go inAxis since it then would be needed forYAxis as well?)

Possibly, one should also renameaxis3d.XAxis toaxis3d.XAxis3D etc. for consistency.