Multistep methods use differences in previous positions instead of velocities. First it uses the Verlet leapfrog method to make Moon. Next it fills Moon.history steps using the multistep method. Then it takes every other position, doubles the stepsize, and generates Moon.history more positions. This is repeated 32 times, bringing the time increment up to the intended size.
Total energy is supposed to be conserved.
It uses BInterpolate.java to build the interpolating polynomial, which in turn uses BMatrix and BVector to do the necessary linear algebra. Dejittering is done by finding the interpolating polynomial for the accelerations, integrating twice, and rederiving the positions. Velocity is found using two points known to have the same jitter error.