Cascade Count Function
Q: How can I do a population count of my coverage area in just one of the counties in my area?
A: For TAP 5.0.1035 systems with a Maintenance Subscription date of November 30, 2004, or later, you can use the Cascade Count feature of the data summary or population count functions.
The Cascade Count feature lets you step through multiple sequential (“cascaded”) counts. After the first count is done (for example, for a coverage contour), the results of that count can be used for the starting point of another count (for example, using the boundary of the county of interest).
For example, suppose you have a coverage contour that you computed in TAP and plotted in HDMapper:
You can use the population count function to get a count of the total population in the contour:
Set the population count settings as desired:
When the count is completed, the summary of the results are displayed, with the option for the cascade operation:
If you just want the total population in the contour, you can click the No button and the results will be displayed:
On the other hand, to use the cascade feature, click the Yes button on the dialog box:
The Data Summation form will be displayed again:
Note that the “Layers to Count” section is disabled. The Cascade function uses the population results from the previous count (in this example, the coverage contour) and only counts values from that result. Therefore, it is not possible to change the selected layers to count after the first selection in a cascade count.
Also note that all polygon layers are available in the Layer pulldown list in the Layer for Selecting Items section of the form:
(On the first instance of a population count, only the TAP field strength coverage layers are available. When the data summation function is used, all layers are always available.)
When you click Continue, the cascade count will continue, and the results will be displayed, again with the option for another cascade iteration:
When you click the No button, the results will be displayed again in a text file:
In this example, by zooming to the south end of the contour, and using the label function, you can see the population centroid points for the computed total:
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Copyright 2004 by SoftWright LLC