An aggregate formatter calculates a set of values and returns a single value. For example, the average
:aggAvgtakes a list of values and returns the average.
The following aggregators are available:
- aggCumSum the cumulative sums, also known as running totals, returns the total sum of data as it grows with series.
Aggregators can be printed as standalone expressions or can be part of loops to compute custom grouping clauses, e.g., sub-totals, cumulative totals.