An erratic tile with believable results. This image was generated using both plotTile, and cycleplot. It shows two tiles. One of the tiles (tile 1) has the usual number of reads for a tile from that run, and a typical breakdown of those reads into the Eland categories. Note the number of reads in the U0 and U1 categories in the histogram on the top right. Nevertheless, as can be seen in Figure 4a this tile has widely varying differences amongst the mean intensities (per cycle). The other tile is the familiar tile 47. The intensity levels are much better behaved, except for the problem in cycle 28. But despite this fact, there is an elevation in the U1 levels on tile 47. This is particularly notable because the lowest intensity cycle on tile 47 is at roughly the same level as the lowest found on tile 1.