Galaxies in 5 h⁻¹ Mpc thick slices of the XY supergalactic plane. From left to right: black lines show the projected distances between true (yellow filled circles) and biased (black filled diamonds), after n_mh. Metropolis Hastings loops but no cooling for the n data points (in the text iteration 1, blue-filled square) and, at the end of all loops (red-filled circles), data point positions. The filled symbol sizes are proportional to velocities in a logarithmic scale. Because errors are large in the left panel, yellow filled circles are harder to distinguish. The algorithm reduces on average errors on data point positions thus on their peculiar velocities, namely, on average, shorter black lines and, by extension, better matching filled symbol sizes of different colors.