## Up to now, have assumed stepsize

*h*is constant.## Clearly prefer choosing

*h*small when*f '*is large, and*h*large when*f '*is small.## The tradeoff is extra trial steps to determine optimum

*h*, but may achieve factor of 10 to 100 increase in stepsize, so it's often worth it.*NRiC*provides a routine odeint() for RK4 with adapative stepsize control. Complicated to use!