xpswmm/xpstorm Resource Center xps

The Ensemble Statistics Utility allows you to view, in a tabular format, the Annual Exceedance Probability (AEP), Mean, Mean Storm, Median, Median Storm, Max, and Max Storm for each Ensemble of an object for a given result type. This feature also allows you to view the Box and Whisker graph that shows the plot of Ensemble versus the Results Value. Moreover, you can export your output into .OUT and .CSV file.

To use the Ensemble Statistics Utility:

  1. Solve the model. For more information, refer to Solve.

  2. Go to Results > Ensemble Statistics Utility. Alternatively, you can click the Ensemble Statistics Utility icon  from the toolbar.

    The Ensemble Statistics Utility dialog will be shown.

    The following columns are displayed in the dialog: 
    • Ensemble Name
    • AEP
    • Mean
    • Mean Storm
    • Median
    • Median Storm
    • Min
    • Min Storm
    • Max 
    • Max Storm

  3. In the Object field, select the object that you want to investigate. By default, the selected object in the Plan View will be displayed. The Object Type field would display the type of object selected.

  4. In the Results Type field, select from the drop-down list the available result type. The following result types are available in HDR and RNF mode:
    • Max Flow (ft^3/s, m^3/s)
    • Max Time to Peak (Hour)
    • Max Velocity (ft/s, m/s)

  5. Click the Box and Whisker button to display the graph of the comparison of storm ensembles of different durations for certain AEP. This plot displays the Ensemble versus Results Value. The Ensemble (x-axis) displays the different Ensembles as shown in the table, while the Results Value (y-axis) displays the value for the Result Type selected. For more information about this plot, refer to Box and Whisker Plot.

    The following options are available in the dialog:
    • Save - This option allows you to save the Box and Whisker plot as a .png, .jpeg, .bmp, or .svg file.
    • Selected AEP - This option allows you to select the AEP, from the drop down, that you wish to display.
    • Show Inner Points - This option allows you to display the inner points in the graph.
    • Show Outliers - This option allows you to display the outliers in the graph.
    • Show Mean Marks - This option allows you to display the mean values as marks in the graph.
    • Show Mean Line - This option allows you to display the mean values as a line in the graph.
    • Display - This option allows you to select the Min, Median, Mean, Max, Third Quartile, and First Quartile values in the graph.

  6. In the EnsembleStatistics Utility dialog, click the OutputFile button to produce an .OUT file. A dialog displaying the file name and location of the output file will be displayed. Click OK to exit.

  7. In the Ensemble Statistics Utility dialog, click the Export Data button to produce a .CSV file. A dialog displaying the file name and location of the CSV file will be displayed. Click OK to exit.

  8. Click Cancel to exit from the Ensemble Statistics Utility dialog.

Box and Whisker Plot

box and whisker plot is a graph that displays information about the range, median, and quartiles. This plot can easily demonstrate whether a distribution is skewed and whether there are potential outliers in the data set, especially for a large number of observations. Box and whisker plots are optimal for comparing distributions because the center, spread, and overall range are immediately visible. Normally, it is represented alongside a number line, similar to the following:

A box and whisker plot is used to summarize a set of data measured on an interval scale. This method is often employed in explanatory data analysis.

In a box and whisker plot:

  • The end lines represent the upper and lower quartiles, so the box spans the interquartile range.
  • The red line inside the box represent the median.
  • The two lines outside the box represent the whiskers, which extend to the highest and lowest observations.