Create a Rolling Period Function for use in Expressions
Imagine if you could easily create a Rolling period expression using a Qlik Function i.e.
Rolling(Field to Roll On, Number of Periods to Roll, Weighting, Forwards (1) /Backwards (0), Go beyond selection (0)/Restrict to selection (1))
e.g. Sum({<Rolling(Months, 3, 0, 0, 0)>}Sales) = Sum Sales rolled backwards on the field Months for 3 periods, no weighting, with results not restricted to date selections. i.e. if dates selected = 2020 Calendar Year, the results for January will include November and December 2019.
e.g. avg({<Rolling(Days, 60, 50, 0, 0)>} Incidents) = Average Incidents rolled backwards on the field Days for 60 days with a weighting of the most recent date being 50% more important than the start date, scaled linearly over the rolling period.
Benefits:
Prevent having to create multiple "as if" fields - which means that our apps will be leaner and faster.
Allows the user to create and compare multiple measures easily e.g. competing moving averages
Prevents the challenges around only accumulating data selected e.g. if I want to show 12 months rolling, accumulation only accumulates the data selected.
Thank you for your feedback on ways to improve our product, if I understand correctly the accumulation modifier released in 2019 November lets you define rolling periods applied on top of your expression as described.
