[Developers] Calculating attributes to a given pickset

[Rogerio Espindola]

Hi people,

I am trying to develop a plugin in which the user would specify the
atribute set
and OpendTect would calculate them to a given pickset. I am studying the 
AttribCalc Class Reference but it has been a hard and time consuming task. 
Could you give me some tips to speed up my comprehension?

I would like to know how to perform the calculations and to store de
atribute values.

Thank you very much.

Rogério.