Solving ODE’s using the SDIRK Method

Hairer, Nørsett & Wanner present a series of ODE’s with a discontinuous forcing function. The equations presented are for the Euler’s motion of a rigid body in a rotational frame of reference. The ODE’s are:

 

 

where

and the initial conditions are

Plotted below is the solution to the Euler’s equations, solved using the SDIRK method.