https://github.com/pydy/pydy will do all this for you with just a few commands.
If you want to use the code generation tools in sympy directly, it may help to replace the functions of time with ordinary symbols. Jason moorepants.info +01 530-601-9791 On Mon, Oct 28, 2019 at 4:04 AM Ash <[email protected]> wrote: > Hello > I am trying to develop equations of motion using sympy of a complex > system. It takes 4-5 minutes to get the mass matrix (M) and coriolis vector > (C). Hence I decided to use sympy's codegen and try to make it fast. > I can write my equations as > > d^2 *q*/ dt^2 = M_inverse (Tau - C - G) > but M, C, Tau (torque) and G(gravity) are defined with respect to state > variables and its derivatives. And I cant figure out how to do it. > > I am attaching a simple two degree of freedom planar robot's code for > easy understanding of my problem. My state variables are the angles q1(t) > and q2(t) (dynamic symbols). There are other variables like lengths, mass, > inertia of the links which are defined as symbols. M(q(t)), C(q(t), dq(t)), > G(q(t)) matrices are derived symbolically (line 14). My doubt is if I want > to play around with the numerical values of the variables in M, C, and G, > how can I efficiently generate code and cythonize and build wrapper? > > Any help would be really appreciated > > Thanks > > -- > 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 [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/eb589af0-2dca-4b8d-bfff-290a4767e20a%40googlegroups.com > <https://groups.google.com/d/msgid/sympy/eb589af0-2dca-4b8d-bfff-290a4767e20a%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAP7f1AjbK%2BKTZJV9z8XO3Y7x_S0%2B7xR969%2BK8GcptG-tgwue%2BQ%40mail.gmail.com.
