Let us get some things clear here. Vector is going to be subclassed from Basic. Also, after seeing the discussions/problems above, Vector + Vector will give an Add on which we can call something akin to a .doit() to result in a Vector. I do not see any problems with this approach.
Next, reference frames. First thing is the distinction between RefFrame class and CoordSys class. Stefan has pointed out that there is no need to implement the classes differently. Okay, then we will have just one, * immutable,* CoordSys class. The parameters required for intialization of kinematic parameters will have to be provided when declaring the coordinate system. New CoordSys object will result from methods like rotate, orient etc. With these suggestions, I do not think that there should be any more structural issues. If there are any more of these issues, please mention them here now and please mention them as early as possible. These changes are justified, I hope, because this module has to play nice with the rest of SymPy. I just feel that we are getting stuck with and spending too much time on things that we shouldn't be taking this much time. Therefore, I request again to all parties involved : Please voice your views/problems with these structural changes suggested so that we can move ahead with things. -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy?hl=en-US. For more options, visit https://groups.google.com/groups/opt_out.
