2 Replies Latest reply on Feb 13, 2019 9:11 PM by Jonathan Drummey

    Independent, Overlaying Maps

    Josh Ciszek



      Attached is a pretty useful analysis for my client of where clients live and the crime in the areas (zipcodes).  As you can see on the dashboard, the user can adjust the client portion based on their program enrollment to change the zipcode density (in blue).  They can also change the date range of crimes to filter the crime circles (red).  Unfortunately, they are linked and changing the date on one (e.g. client enrollment) impacts the crimes.


      I'm sure it is due to how I'm blending, but is there a way to have these 2 parameters act independently.  In other words, the crime visuals don't change because of changing the customer enrollments...



        • 1. Re: Independent, Overlaying Maps
          Patrick Van Der Hyde



          This data is linked on postcode and the crime  details are at the level of postcode.  Your post mentions parameters but there are no parameters associated with either of these data sources but instead two filters for date ranges.  The date range filters are limiting the available data to make the views.  I'm wondering if either of the data images could be represented as static data in a picture/image so the other data could be dynamic? 


          Thank you for sharing the workbook example to hep the community to see the issue. 



          • 2. Re: Independent, Overlaying Maps
            Jonathan Drummey

            Hi Josh,


            A Tableau data blend is like a post-aggregate left join. So even though we have two separate data sources *filters apply to both*, just like they would if we'd done a join of the sources.


            The workaround in this case is not to blend or join, but instead to union, add the range filters, and configure the range filters to keep Null values (from the other side of the union). Since these are two different files you'll probably need to do the full outer join on 0=1 technique covered in this post Dual Axis Mapping - Many Ways. Then you can add the two range filters & keep Nulls technique covered in this post Creating a Dynamic Range “Parameter” in Tableau | Drawing with Numbers.