I thought I would share a simple calculation I created in a document I'm working in:
I have a document loading various elements of data including an expense amount. I wanted to create a small statistic box in the opening screen with YTD expenses without the user needing to select the Category "Expense", etc. So here is the calculation I used:
SUM({$<Year = {$(=max(Year))}, Category = {'Expense'}>} [Expense Amount])
I hope you find this useful.
Josh
