I have used sympy.physics.mechanics, Kane's method, on many, surely over 100 or 200 simulations. As you say, it is awsome! Which book are yopu referring to, if I may ask? Calos Roithmyr's book?
frank....@gmail.com schrieb am Montag, 21. Juli 2025 um 19:09:12 UTC+2: > I was hoping to be able to manipulate vector objects in lieu of arrays of > components. When you work on a component basis, it's gets hard to recognize > cross and dot products when there chain of dots and crosses. It seems like > they could be another symbol class that has a slightly different set of > rules. I wonder if sagemath has something, although using sagemath seems to > be way more complicated... > > I am using the mechanics pkg (it's awesome!). I going through a text on > Kane's method and trying to do every problem in the book with sympy. I run > into difficulties with some of the proofs where you have to expand multiple > dot product, cross products, and triple products. Currently I default to a > tablet and just do it by hand. > > I can't imagine grinding on all the algebra by hand...you'd need to take > my belt and shoelaces... > > On Monday, July 21, 2025 at 12:08:47 PM UTC-4 asme...@gmail.com wrote: > >> Yes, I think the stuff in mechanics is the best way to achieve what >> you are looking for right now. It might be good to try to unify some >> of this stuff at some point, since much of what is in mechanics isn't >> really specific to mechanics or even physics. >> >> Aaron Meurer >> >> On Sat, Jul 19, 2025 at 10:44 AM Peter Stahlecker >> <peter.st...@gmail.com> wrote: >> > >> > In sympy.physics.mechanics, I can create, say, three point P1, P2, P3 >> > make >> > u = P1.pos_from(P2) >> > v = P2.pos_from(P3) >> > >> > and can get >> > w = u.cross(v) >> > >> > but maybe I am missing a point. >> > >> > asme...@gmail.com schrieb am Samstag, 19. Juli 2025 um 18:10:36 UTC+2: >> >> >> >> I would also suggest using matrix expressions for this. The main issue >> >> is that matrix expressions currently don't have a Cross operation. It >> >> wouldn't be too hard to make one by subclassing MatrixExpr. I would >> >> suggest opening an issue about this. >> >> >> >> The diff thing is another issue because currently there isn't a way to >> >> represent functions in the matrix expressions >> >> https://github.com/sympy/sympy/issues/5855 >> >> https://github.com/sympy/sympy/issues/19265 >> >> >> >> Aaron Meurer >> >> >> >> On Sat, Jul 19, 2025 at 1:24 AM Jason Moore <moore...@gmail.com> >> wrote: >> >> > >> >> > I do not think there is a VectorSymbol type of object. If there was >> you could imagine doing things like: >> >> > >> >> > R = VectorSymbol('R', 3) >> >> > r = VectorSymbol('r', 3) >> >> > R.diff(t).cross(r.diff(t)) >> >> > >> >> > We do have a MatrixSymbol object that may do what you desire. You >> can create nx1 column matrices and then do such operations. >> >> > >> >> > Jason >> >> > moorepants.info >> >> > +01 530-601-9791 <(530)%20601-9791> >> >> > >> >> > >> >> > On Thu, May 29, 2025 at 11:28 PM Frank Senkel <frank....@gmail.com> >> wrote: >> >> >> >> >> >> Does sympy handle vector expressions vs instances of specific >> vectors?..so AxBxC vs [a1,a2,a3] x [b1, b2, b3]...something like this. >> >> >> >> >> >> -- >> >> >> You received this message because you are subscribed to the Google >> Groups "sympy" group. >> >> >> To unsubscribe from this group and stop receiving emails from it, >> send an email to sympy+un...@googlegroups.com. >> >> >> To view this discussion visit >> https://groups.google.com/d/msgid/sympy/b22199b5-810b-4371-8479-eabd71e30d0dn%40googlegroups.com. >> >> >> >> > >> >> > -- >> >> > You received this message because you are subscribed to the Google >> Groups "sympy" group. >> >> > To unsubscribe from this group and stop receiving emails from it, >> send an email to sympy+un...@googlegroups.com. >> >> > To view this discussion visit >> https://groups.google.com/d/msgid/sympy/CAP7f1AiS2juGowfs0%3DYQcyR4mgaDZsHjRoZtwXAWEToi2r8nvg%40mail.gmail.com. >> >> >> > >> > -- >> > You received this message because you are subscribed to the Google >> Groups "sympy" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> an email to sympy+un...@googlegroups.com. >> > To view this discussion visit >> https://groups.google.com/d/msgid/sympy/70440eaa-7bc7-4ab8-a5d6-06bc7abf53f9n%40googlegroups.com. >> >> >> > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/sympy/395a87ed-fab2-4de1-9fdb-f2b662dc924bn%40googlegroups.com.
