Modern scientific experiments and simulations often produce vast amounts of data; they are aided by the continuous gains in computing performance and reductions in storage costs. However, the nature of the data produced by experiments and simulations is usually symbolic, and it becomes harder and harder for humans to comprehend such data sets directly, due to their increasing size. Figure 10.1 illustrates the point with an example. On the left-hand side, we have a numeric matrix, and on the right-hand side, we have the mapping of the numbers onto grayscale values, with a specific range coding. Once again, a picture is worth a thousand words!