Hello, I am having some doubts on how to use subs() in sympy. My aim is to do lagrangian mechanics which involves differentiation.The code below is a cooked up one but I guess it would serve the purpose.
Please look at the code below from sympy.physics.mechanics import * import cvxpy q1, q2 = dynamicsymbols('q1 q2') q1d, q2d = dynamicsymbols('q1 q2', 1) L = q1*q1d + q2*q2d print L.subs(q1, 2).subs(q2, 1).subs(q1d, 3).subs(q2d, 7) # EXPECTED ANSWER: L = 2*3 + 1*7 = 13 # ACTUAL ANSWER: L = Derivative(1, t) + 2*Derivative(2, t) Please let me know how to modify the code to get the expected answer Thanks Ash -- 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 post to this group, send email to sympy@googlegroups.com. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/935d0daa-9dc6-4174-990d-d0d7172612ae%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.