5 Replies Latest reply on Jun 22, 2016 2:55 PM by Matt Lutton

    LOD Calculation Changes on Dimension

    Phillip Black

      I have an LOD Calculation that changes on a Dimension, but should not. Any reason why that might be? My FIXED calculation includes all of my filters.

       

      Workbook is attached - Thank you for any help!

        • 1. Re: LOD Calculation Changes on Dimension
          Ashish Chaudhari

          Hi Phillip,

           

          Few quick questions. As per you LOD calculation this are the values that I am able to see for below mentioned filters where Channel, Country and Platform ate the parameter that you have created.

           

          Date Range - 7 May, 2016 to 13 May, 2016

          Channel - All (Organic, Paid)

          Country - AU

          Platform - All (Android, IOS)

           

           

          For Above same values I have not used any of the parameter/filters. I am directly using the quick filters and I am getting below result which is not matching with your numbers.

          Coming back to your question. Can mention the dimensions/filters using which your data should not change?

           

          Let me know if I have missed anything in this.

           

          Thanks and Regards

          -Ashish Chaudhari

          • 2. Re: LOD Calculation Changes on Dimension
            Phillip Black

            Hey Ashish - thank you for replying.

             

            That's my mystery! Why are the numbers different? I want my FIXED LOD to exclude country, platform and channel.

            • 3. Re: LOD Calculation Changes on Dimension
              pooja.gandhi

              Philip - you'll want to fix the calculation at a level of only install cohort day and remove other fields from the expression. If you include those other fields, the breakdown is more granular. Is this what you mean?

               

              • 4. Re: LOD Calculation Changes on Dimension
                Phillip Black

                Yes, but the FIXED field needs to include those other items - channel, platform, and country - because I toggle them and calculations built on this LOD need to change. For example,

                 

                SUM([Revenue])/SUM({FIXED [Install Cohort Day], [Channel], [Country], [Platform]: COUNTD([device_token])})

                 

                 

                 

                If I toggle channel then denominator will change (what I want), but if you leave it like

                 

                SUM([Revenue])/SUM({FIXED [Install Cohort Day]: COUNTD([device_token])})

                 

                Then the denominator will stay the same, despite changes in the filter (not what I want)

                 

                 

                 

                Does this help?

                • 5. Re: LOD Calculation Changes on Dimension
                  Matt Lutton

                  Hi Phillip,

                   

                  I don't have time to drill into your particular situation, but I believe studying/reading the following will help you understand filter behaviors, as they relate to LOD Expressions:

                   

                  What’s new in Tableau 9.0? Part 2 – Level of Detail Expressions « Bora Beran

                   

                  This was written by the Program Manager whose team developed these calculations, and its a go-to resource of mine when trying to troubleshoot LODs that aren't working as I expect them to.

                   

                  Best wishes.