This article describes how to use the Difference from Previous Value analytic function in Arcadia Enterprise.
We are using the Basic Visual for Aggregates to demonstrate how to use the Difference from Previous Value analytic function.
sum(population)
field on the Y Axis shelf.In the Analytic Function: Difference from Previous Value modal window,
Under Select the sort order, you can specify the order of sorting. This order specifies what the previous row is, and the row where the value is taken. If your visual already specifies sorting order, these values appear in the modal.
You can add additional sort parameters, by clicking the (add/plus) icon.
Here, leave the default order: year ascending, followed by country ascending.
[Optional] If you examine the expression in the Enter/Edit Expression interface, it shows that the function has the following form:
sum([population]) - LAG(sum([population]), 1) over (partition by [year]
order by [year], [country])
as 'difference from previous value(population)'
Click Refresh Visual.
Notice the change to the appearance of the visual, and the change in values that appear on the tooltip.