On Sat, Mar 19, 2011 at 1:36 AM, Aaron S. Meurer <[email protected]> wrote: > > On Mar 19, 2011, at 2:22 AM, Tim Lahey wrote: > >> 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. > > Well, integrals is just the integration part of calculus, and there is enough > of that alone to justify a separate module (trust me). > >> >>> 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. > > Hmm. I'm not sure about this idea. It requires moving a lot of stuff > around. Potentially, if this module could get quite large with a bunch of > future enhancements, then it would make sense. I supposed that DEtools and > PDEtools are quite large in Maple. > > Does anyone else have an opinion on this?
Let's move stuff around when we have some stuff to move. Right now, I think it's not a problem to solve. Ondrej -- 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.
