Difference Pivot Table Empty Cell

Hello,

I am trying to calculate the difference between units sold of some products on 2 consecutives weeks, the problem is that, at some weeks, my table has not any register of a sold, so, on the pivot table some lines are empty. Because of this, when I try to do the difference between then, it returns me a null value.

Example

Hello,
You need to convert nulls to 0s before.
changenull = ifelse(isNull(Units),0,Units)

Hi,

How can I calculate the difference between 2 columns in a pivot table when the column’s field is not a date data type?
I know there is a new functionality of table calculation that can help. The problem is it replaces the original aggregated metric with the table calculation function result and not adding it side by side.

Regards,
Amihai