Trace plots of an example chain, chain number 10. Left: the likelihood values of the observational constraints. The solid blue line is the total likelihood, which is the sum of all other solid lines that indicate components of the likelihood. The dashed lines are the prior on the initial white noise fields s_LR and s_HR. Right: The masses of the Milky Way and M31 along the chain. The greyed-out lines indicate values of the masses before applying the correction from Figure C.1. This particular chain was considered warmed up by sample 760 according to the criterion of Section 3.3.