On Fri, Jun 17, 2011 at 15:25, Ondrej Certik <ondrej.cer...@gmail.com>wrote:
> Yes, that's what I had in mind. All these functions (like spherical > harmonics, Legendre polynomials, ...) should be both symbolic and the > actual result. > I think we might be able to use the eval=False option when > constructing the class, so that it plays well with the sympy > machinery. > In any case, this is easy to fix. > > The hard part is to actually calculate the correct result. Sean, did > you make any progress? > > I did. Attached find the working version of the Wigner small d > function. See the comments in the function -- I have found some wrong > equations in Varshalovich (or my understanding of them is wrong). But > I have figured out the right ones, see the comments, and I have > checked them with the tables in Varshalovich, and it agrees, both for > general beta, and for beta=pi/2. My function returns the trigonometric > expressions in the form sin(a*beta/2), while Varshalovich uses powers > of sin(beta/2). But they are equivalent. > > If you run the script, it prints the tables, so you can directly > compare it to Varshalovich. Sean, can you compare the speed of > evaluation for general beta, using Brian+your fix, versus my > implementation? Let's use the one, which is faster. > > > Ondrej > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sympy@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > > I played around a bit with some other equations to get d, and while they would work, there were still problems getting them to simplify nicely. I'll work out the equations to make sure I understand what is going on and can check the speed of the evaluations. Sean -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
