Uncertainty in the A+T and T+C proportions of the mosaic classes. The circles show the position of the classes used to initialise the final HMM training run. The radius of these circles is the standard error of this initial position calculated from the positions of the classes averaged to produce these initial classes--compare Figure 7. The line from each circle shows the position of the class after the final HMM training run, which is also shown in Figure 1A. The figure shows only the region T+C > 0.5--the omitted region mirrors the region shown. The statistical robustness of the method for deriving the mosaic classes is demonstrated by i) the consistency of the results of the preliminary runs shown by the small size of the circles and ii) the small difference between the classes at the beginning and end of the final training run shown by the short length of the lines.