[sympy] how to denest the sum symbol in sum of sympy.Sum

Hi: I want to use power series to solve second order differential equation. Albeit sympy.ode already has 2nd_power_series_ordinary and 2nd_power_series_regular to do the job, it does not provide the recurrence relation of coefficient. What I actually need is the recurrence relation of

Re: [sympy] Re: 3D pendulum and equations of motion of multi-body systems (KanesMethod)

Right now I'm trying to get the equations of motion of a 3D pendulum system (spherical pendulum) and I want to describe the system using the (x,y,z) coordinates of the mass as well as its attitude (phi, theta, psi),

Re: [sympy] Re: 3D pendulum and equations of motion of multi-body systems (KanesMethod)

Nuno, If you provide a sketch of the system, a description of the system, and what you are hoping to accomplish that will help us be able to help you. Jason moorepants.info +01 530-601-9791 On Wed, Aug 10, 2016 at 7:06 PM, Nuno wrote: > In the first place thanks for