The Aggregates property gives access to the Aggregates collection. The Aggregates collection holds a collection of Aggregate objects. An aggregate function is a function where the values of multiple rows are grouped together as input on certain criteria to form a single value of more significant meaning or measurement such as a set, a bag or a list. The Aggregate object is identified by an unique key. By default, the Aggregates collection contains the "sum", "min", "max", "count", "avg" or "unique" Aggregate objects. Use the Add method to add a new Aggregate function/object to the control. Use the FormatValue/FormatResult property to convert/format the value/result of the Aggregate function. The PivotColumns or PivotTotals property to display aggregate functions on the columns. Use the FormatPivotAggregate / FormatPivotTotal property to display aggregate functions in a different format.

The following screen shot shows the Aggregate objects in the control's context menu:

By default, the Aggregates collection contains the following elements:

• "sum", summation is the operation of adding a sequence of numbers; the result is their sum or total
• "min", minimum is the smallest value
• "max", maximum is the largest value
• "count", counts the number of objects in the set
• "avg",  average is the arithmetic mean, which means sum of all numbers divided by the count.

For instance:

• you want to get the total for negative values or to count the positive value only. In this case, you can add a new Aggregate object such as Aggregates.Add("negative", "sum").FormatValue = "value < 0 ? value : 0", and so the negative Aggregate function gets the total of negative values only. 
• The  Aggregates.Add("positive", "sum").FormatValue = "value < 0 ? 0 : 1", counts the number of positive values.