Finding acceleration using ODE45.

I am solving a set of equations of motion using ODE45. ODE45 works perfectly to give me the displacement and velocity of the moving object. However, I would like to calculate one of the force components and for that I need the acceleration. How Should I go to work to find the acceleration from ODE45.

[Torsten]

But you prescribe the acceleration to get velocity and displacement, don't you ?

[Philip Bothma]

You are completely correct. Thankyou!! I did not use my thinker there.