Color mapping. Heat maps produced using the simulated data from Figure 1 and Euclidean distance. In (a), the colors are mapped to the original data, in (b) the colors are mapped to row-scaled data. Using row-scaled data, it is much easier to see that the patterns in A and B are the same. Using the original data, the differences in intensity between each row dominate the image. By default, data is row-scaled.