If you read the forum post on 'Creating your own Territory Map Layers', then you were introduced to the AWhere 'Aggregate Add-In' (click here to read that post if you have not already).
I thought I would add to the explanation of the Aggregator Add-in, by explaining another aspect of what the Aggregator does/can do. In the previous post, I basically just covered how an aggregation creates new (larger) polygons by dissolving the boundaries between neighboring (smaller) polygons. So, that covered the ‘geographic’ aspects of what an Aggregation does; but know that there can also be (but does not always have to be) a mathematical aggregation that can be performed along with the geographic aggregation.
If the features being aggregated have any numeric attributes, you can choose to have those numeric attributes mathematically aggregated, so that their sum* is appended as an attribute to the newly created (larger) polygon.
(*Note that although you would typically perform a ‘sum’ in this situation, you can also opt to calculate other derived statistics when performing an aggregation of features, including ‘maximum’, ‘minimum’, ‘mean’, and ‘standard deviation’…refer to the Aggregate Add-In help documentation (accessed from the Aggregate Add-In’s interface) for more about these options…refer to ‘Step 3’ of the add-in.)
In this simple visual example below, using the counties of Massachusetts once again, you can see that each county has been given a numeric value (labeled on the county for visual demonstration on the upper map below)…we will imagine that these are ‘Projected Sales’ figures for next year. When the Aggregation is performed…not only does the geographic (physical) aggregation take place to create a new map layer of ‘sales territories’, but the mathematical aggregation is performed as well (the 'sum' option was selected). As you can see below, the result of the aggregation shows the new aggregated polygons, and also, each polygon has been labeled (again, for visual demonstration purposes only) with the sum of the ‘Projected Sales’ figures from the counties that were combined to create the new aggregated polygons.
