In the example, I have asked that the plotting symbol be a diamond instead of the default circle. The user has a choice of quite a few plotting symbols. In each plot there is a menu button that has further useful options. One can select or deselect points with the mouse, highlight certain points, save the plot as a postscript file etc. I will only discuss a single feature, that of linking .
Linked plots are a way of sharing information between plots.
Consider for example, figure 2, where we have a plot of requests versus time as well as a histogram of requests . If you enable linking by choosing the Link View item in the menu in each plot, selecting a vertical bar in the histogram by dragging the mouse with the button pressed causes the corresponding points in the line plot to be highlighted. You might have to peer at the figure to see that the point where the highest peak occurs is highlighted since it corresponds to the highlighted histogram bar. Linking is extremely useful in viewing multidimensional data since one can get a better idea of how the same group of points can be projected in different views. The use of the quote is essential, otherwise the interpreter would assume that mean is a variable and try to evaluate it.