difference
The difference function calculates the difference between a measure based
			on one set of partitions and sorts, and a measure based on another. 
The difference function is supported for use with analyses based on
				SPICE and direct query data sets.
Syntax
The brackets are required. To see which arguments are optional, see the following descriptions.
difference (measure,[ sortorder_field ASC_or_DESC, ... ],lookup_index, ,[ partition field, ... ])
Arguments
- measure
- 
						An aggregated measure that you want to see the difference for. 
- sort order field
- 
						One or more measures and dimensions that you want to sort the data by, separated by commas. You can specify either ascending ( ASC) or descending (DESC) sort order.Each field in the list is enclosed in {} (curly braces), if it is more than one word. The entire list is enclosed in [ ] (square brackets). 
- lookup index
- 
						The lookup index can be positive or negative, indicating a following row in the sort (positive) or a previous row in the sort (negative). The lookup index can be 1–2,147,483,647. For the engines MySQL, MariaDB and Aurora MySQL-Compatible Edition, the lookup index is limited to just 1. 
- partition field
- 
						(Optional) One or more dimensions that you want to partition by, separated by commas. Each field in the list is enclosed in {} (curly braces), if it is more than one word. The entire list is enclosed in [ ] (square brackets). 
Example
The following example calculates the difference between of sum({Billed
					Amount}), sorted by Customer Region ascending, compared to
				the next row, and partitioned by Service Line.
difference( sum( {Billed Amount} ), [{Customer Region} ASC], 1, [{Service Line}] )
The following example calculates the difference between Billed Amount
				compared to the next line, partitioned by ([{Customer Region}]). The
				fields in the table calculation are in the field wells of the visual.
difference( sum( {Billed Amount} ), [{Customer Region} ASC], 1 )
The red highlights show how each amount is added ( a + b = c ) to show the difference between amounts a and c.
