Here is a first go that uses the quantum stuff in sympy.physics.quantum https://github.com/ellisonbg/sympy/commit/096da85aedc256203643a69b88e30e9ad3859683
I will add tests and the anticommutator equivalent and submit a pull request soon. Cheers, Brian On Thu, May 26, 2011 at 1:24 PM, Brian Granger <[email protected]> wrote: > Rajeev, > > Hi, great question. Just to understand the context. What are x and > y? Are they a creation/annihilation operator pair? As you may know, > we have quite a bit of code in sympy.physics.quantum for handling > various things from quantum mechanics in a symbolic manner, include > commutation relationships. One thing that we have is a > commutator/anticommutator aware bubble sort algorithm that could > probably be adapted to do what you want. > > But, before we dive into that can you say a bit more about what > exactly you are trying to do? > > Thanks, > > Brian > > On Mon, May 23, 2011 at 9:55 PM, Rajeev Singh <[email protected]> wrote: >> Hi, >> I asked this question on sage mailing list already and it seems appropriate >> to ask here as well. I wish to simplify some calculation that appear in >> quantum mechanics. To begin we use non-commutative variables as - >> sage: x, y = sympy.symbols('xy', commutative=False) >> sage: sympy.expand((x+y)**3) >> x**2*y + y**2*x + x*y**2 + y*x**2 + x**3 + y**3 + x*y*x + y*x*y >> I want to impose the commutation relation [x,y]=1 and bring the expression >> to normal form (i.e. in all terms y appears before x, e.g. x*y gets replaced >> by y*x + 1). Is it possible to do this? >> If not then can I get the expression such that x*y**2 appears as x*y*y? >> Thanks in advance. >> Regards, >> Rajeev >> >> -- >> 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. >> > > > > -- > Brian E. Granger > Cal Poly State University, San Luis Obispo > [email protected] and [email protected] > -- Brian E. Granger Cal Poly State University, San Luis Obispo [email protected] and [email protected] -- 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.
