Often a purely graphical representation of a large data set needs to be tied to a dis- play of the numerical values in that data set. X Image provides a useful tool for establishing a precise correspondence between colored pixels in a raster map and their corresponding numerical values. With the raster display of the data set open, return to the window shown in Figure 3 and left click on the option Display Data Set. A spreadsheet of your data, similar to that in Figure 7 will appear. Left clicking on the raster map will put the shaded marker in the spreadsheet over the value to which that pixel corresponds. Similarly, left clicking on a numerical value in the spreadsheet places a small dot on the corresponding pixel in the raster map. This will work for both the polar and the cartesian graphs.