The new quantum module looks very nice, thanks for doing all that work! to., 10.02.2011 kl. 21.02 -0800, skrev Brian Granger: > Øyvind and others interested in sympy.physics.quantum, > > As you have seen the quantum stuff is in. I have been looking at > secondquant to see how it will be to move it to use the new stuff. I > think a significant amount of the logic in secondquant will simply go > away. The following classes/functions in secondquant are already > implemented in the base layer now: > > Dagger, KroneckerDelta, apply_operators, InnerProduct, Commutator, matrix_rep > > In addition, much of the logic that is in the state and operator > classes is implemented in a generic way. The main thing that I don't > see how it will work is all of the fermi level stuff. Because things > like KroneckerDelta are completely general (I am even going to move it > outside of the quantum stuff), we need to localize the fermi_level > stuff to the fermionic objects. I don't have time to work on this > right now, but I at least wanted to start the design discussion. We > should also move secondquant to the quantum package.
It will be great to clean up the SQ module by importing stuff from quantum instead. I also think it should not be to difficult to move the fermi_level logic into contraction(), wicks() and the simplification routines. Some of the methods that handles fermi_level logic, is not even in use, so it will be good to get rid of them. As you suggest the KroneckerDelta should be moved out of the module. In fact, the way it is used in order to restrict indices to below/above fermi, may not be optimal. It may be possible to define fermi_level as a Symbol, and use assumptions like p<=fermi_level. If that approach is feasible, the restriction of an index, could instead be done using a Heaviside step function. I am thinking aloud here, but let's use this opportunity to rethink the whole thing. Cheers, Øyvind -- You received this message because you are subscribed to the Google Groups "sympy" 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?hl=en.
