2 Replies Latest reply on Jun 29, 2015 3:40 PM by Thorsten Vogt

    Effect of filtering on first days of "rolling" n-day table calculations?

      For non-proprietary illustration purposes, let's say I was a waiter who wanted to calculate my rolling 7-day tip rate.

       

      Using Tableau, I can (suprisingly easily!) create rolling 7-day tip amount and bill amount totals, and divide them to create a rolling 7-day tip rate (tip amt/bill amt).

       

      What I'm running into is an issue when I try to limit the display by filtering for a particular month. What seems to be happening is that the filter for one month, say July 2011, eliminates the entries from the prior month (June 2011) that are needed to compute the rolling 7-day tip rate for the first 6 days of the current month (July 2011). As such, the curve for the first 6 days of the month are not "smoothed" as they could be.

       

      Is there a clever trick to get around this (filter on one range, compute on another) or a different way of accomplishing this?

       

      Thanks!