Peak velocity inside the NanoRocks trays: measured manually for one shaking cycle (averaged over 10 particles, black asterisks); computed via the automated tracking (averaged over all tracks, blue diamonds); and with the statistical method described in the text (triangles). The velocity values determined statistically are shown for the data set that was also tracked manually (black triangles), and averaged over 178 shaking cycles (red triangles with the mean absolute deviation shown as error bars (red). Red and black triangles overlap for most trays.