Comment #4 on issue 3199 by [email protected]: Finish implementing density operator/matrix
http://code.google.com/p/sympy/issues/detail?id=3199
For Trace I would pick something in sympy.physics.quantum that is reasonably close and use that as a template.
I think the qubit focused density matrix will still take a sequence of states and probabilties as the base class does.
The partial trace logic in qubitdensity only works for qubits. The base density class will need to have its own logic to handle general partiall traces when the states are TensorProduct instances. The "specialized" partial trace I was referring to is the logic in qubitdensity. It is specialized because it won't work for general density matrices.
You can currently build density matrices of TensorProduct states, but you don't have the logic to take partial traces of those.
I don't think we can change the fact that qapply expands its arguments. Our code base uses this fact throughout and many things would break if we stopped doing this. Whatever we do with density matrices will have to work around that. I guess I don't see why we this needs to change to get density matrices working. Can you clarify this point?
-- You received this message because you are subscribed to the Google Groups "sympy-issues" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy-issues?hl=en.
