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" or "avg" 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.