On 03-19-2011, at 4:07 AM, Aaron S. Meurer wrote: > On Mar 19, 2011, at 2:01 AM, Tim Lahey wrote: > >> On 03-19-2011, at 3:48 AM, Aaron S. Meurer wrote: >> >>> On Mar 19, 2011, at 12:30 AM, Tim Lahey wrote: >>> >>>> >>>> My thought would be to create a new module for calculus of variations >>>> (probably called calcvar) and put it under that. That way, more can be >>>> added to it and I can't really see a current module (other than possibly >>>> physics) that it fits in. I've forked the main repository, so I'll see >>>> about doing this. >>>> >>> >>> What other things would eventually go in the module? >>> >> >> Well, there are various tests that could go in the module. That's what's in >> the Maple Calculus of Variations package. What I'd like to see is the >> ability to take a variation. I've implemented something simple along these >> lines in Maple already. It's not particularly robust at the moment though. > > I'm not sure if I understand what you mean by "tests".
There are various functions to characterize the functionals. Maple's calculus of variations help is, http://www.maplesoft.com/support/help/Maple/view.aspx?path=VariationalCalculus The package has a test to see if the integrand is convex. There are other similar tests that could be there but aren't. There are also other functions similar to the Euler-Lagrange that could be included (e.g., Jacobi, Weierstrass). I'm not particularly interested in these, but others may be. > >> >>> It definitely shouldn't go in physics, since calculus of variations is >>> useful to more than just physics! >> >> I agree. The only other place it kind of fits is the integrals module, but >> that's not really right since the Euler-Lagrange equation is a differential >> equation, not an integral. I find the naming of that module somewhat >> unfortunate since I'd rather see a calculus module with integrals, ODEs, and >> PDEs in it. If that was the case, I'd put the calculus of variations stuff >> in there. > > It actually makes sense to me to have all the solvers together (solvers, ode, > pde, recur, etc.). > > integrals does indeed deserve its own module, because it will get very large > as more and more of the integration algorithm is implemented. > It's more that I think integrals should have been called calculus instead. > Anyway, where do you think it should go given the way things are? I don't > have any ideas. > Right now, it doesn't really fit anywhere, that's why I think it should be a new module. If we create a new "calculus" module then we could put the calculus of variations stuff in there and tools to manipulate differential equations that aren't strictly about solving DEs. Like Maple's DE and PDEtools packages. Cheers, Tim. --- Tim Lahey PhD Candidate, Systems Design Engineering University of Waterloo http://about.me/tjlahey -- 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.
