3 Replies Latest reply on Sep 20, 2018 3:09 AM by Yasmin Nouichi

    Combining a point and polygon map

    Yasmin Nouichi

      I have created two maps with each a separate data source. The polygon map has a kml file as the source and is joined with a Google sheet. The point map uses a different Google sheet with addresses that contain latitude and longitude. I have been able to create both maps separately but struggle combining them into one. I can create a dual axis map, but I can't get the points and the polygons to appear at the same time. I have tried joining the data sources (under "District name") but the dual axis map fails to generate there too.


      I have searched the forums extensively and know it is possible - could someone help me out please? Workbook attached. This other topic explains my problem really well: Dual Axis Map with different data sources




      Yasmin Nouichi

        • 1. Re: Combining a point and polygon map
          Jim Dehner

          Good morning

          In 2018.2 Tableau simplified the process to accomplish this

          see the link and view the Spatial Join feature



          Tableau 2018.2 New Features




          If this posts assists in resolving the question, please mark it helpful or as the 'correct answer' if it resolves the question. This will help other users find the same answer/resolution.  Thank you.

          • 2. Re: Combining a point and polygon map
            Sarah Battersby

            Hi Yasmin,


            To create the dual axis map, it looks like you just need to join the two data sources together, instead of using them as separate data sources.  I suggest joining on a calculated field (0 = 1) with a full outer join so that you end up with a single data source with all rows from both tables.  There are some instructions here: Dual Axis Mapping - Many Ways  See the section on spatial file + csv. 


            I cannot access the source for your Google sheet data to make an example, but there are a few example workbooks attached to the post that I linked above that might be helpful in solving your problem.


            If you need to be able to identify which point falls inside each polygon, as Jim noted in his earlier response, you will want to try the spatial join functionality in Tableau 2018.2 or later, though to use this you will have to convert your Google sheet with latitude and longitude values into a spatial file type (e.g., shapefile, KML, etc.).



            Tableau Research

            • 3. Re: Combining a point and polygon map
              Yasmin Nouichi

              Thank you so much Sarah, that indeed solved my problem.