4 Replies Latest reply on Nov 29, 2017 7:37 PM by Zhouyi Zhang

    Problems with Null Data in Nested Window_sum LOD function

    Matthew Theis

      Hello Community!


      I've run into a problem that I can't seem to figure out.  I'm trying to create a rolling 12 month percent of total calculation for hospital system preferences.  I have used the ZN function to help with NULL data, but it doesn't seem to be giving me the results that I need.  I've tried to work my way through finding the source of the problem, and I think I found it lies in the denominator of the calculation.  For this part, I need to basically have sum(weight) for all System Groups for each MY(My Custom Date).  As you can see in the attached .twbx, things appear to be working just fine, until October 2016, where "All Others" has a NULL value.  Denominator reads 198.1, where it needs to read 215.3, like the others.  I can't seem to figure out why Tableau is doing this, nor understand how to fix it.  Please help!




      Matthew Theis