Matt, Sam, Eric, Britton,

Thank you for all the previous infos (projections and 2D profiles). 
Now I have a clearer vision of these features. 
Sam, you are right, the derived field is created before the radial binning.
I will let you know if I have further doubts (for sure).

As I said to Matt previously, I want to extend my congratulations to all the YT developers.
You are doing a great job.