A Fan Graph consists of multiple lines in the Y axis for multiple scenarios (or multiple years for one variable) graphed in the X axis. The variables graphed in the X axis can be successive years for any simulated output variable that Simetar© collected data for during simulation. Alternatively, the variables graphed on the X axis can be the same simulated variable but for different scenarios or years. The purpose of a Fan Graph is to show the effect of risk on a variable over time or across scenarios.
A Fan Graph showing the simulated mean and percentiles or confidence interval lines about the mean can be developed using the Fan graph of alternative stochastic scenarios icon in Simetar©. The range of variables to be graphed on the X axis must be specified in the Select Ranges to Graph box (Figure 5). The variables (scenarios) must be specified in the order they are to appear in the graph. For example, if the graph is for 10 years of a probabilistic forecast, specify the 10 variables across the, say, 500 iterations as the selected range to graph. If the variables are not contiguous, they can be specified one at a time using the Add box.
Fan graph of alternative stochastic scenarios
|Figure 5. Fan Graph Dialog Box.
The Fan Graph dialog box (Figure 5) provides boxes to specify up to six percentile or confidence lines about the mean. The individual lines to add to the Fan Graph must be specified as fractions, such as 0.05 and 0.95 would result in a graph with 3 lines: the mean, the 5 percentile and the 95 percentile lines. Once the Fan Graph has been developed, you can dynamically change the graph by editing the percentile values in the output table. For example, if the 5% and 95% lines need to be changed to 1% and 99%, simply change the 0.05 to 0.01 and the 0.95 to 0.99 in the Fan Graph output table. Changing the percentile causes Simetar© to re-draw the graph. See Step 8 in DemoSimetar-Ana for an example of a fan graph.