The Q-Q Plot can be accessed from the Result Graphs sub menu of the Fit menu. It is activated only after specific distributions have been chosen.
The Q-Q plot, as shown below, is a plot of the input data [straight line] in the Data Table versus the value of x that the fitted distribution must have in order to give the same probability of occurrence. This plot tends to be sensitive to variations of the input data in the tails of the distribution. (see Law&Kelton1) If more than one distribution was fit to the input data, the list at the top right will allow a choice of available Q-Q plots of fitted distributions. Clicking a distribution will add that distribution to the plot. The list at the bottom right contains the densities plotted for comparison. Clicking a distribution in this list will remove that distribution from the plot. The legend will contain color-coded identification of the plotted distributions and input as shown in the second plot.
This graph, as with all graphs in Stat::Fit, may be modified, saved, copied, or printed with options generally given in the Graph Style , Save As, and Copy commands in the Graphics menu.
1. "Simulation Modeling & Analysis", Averill M. Law, W. David Kelton, 1991, McGraw-Hill, p 374
