2 Replies Latest reply on Dec 4, 2012 5:41 AM by Seth Redmore

    Using my own latitude/longitude for chloropleth (filled) maps?

    Seth Redmore

      So, this is my first foray into geocoding.  Yay! 

       

      I've got a bunch of lat/long coded twitter data that I've processed for sentiment.   I want to create a filled map.  In case anyone is curious, I used our software (http://www.lexalytics.com) for the text processing - and am very interested in comparing notes with other folks using Tableau for visualizating text-heavy content. 

       

      Anyhow...

       

      My understanding from another thread is that this is not directly possible - and from looking at the examples, I see that I need to set a level of detail using something like "state" to get the fill to work.

       

      So.... Do I need to actually pre-compute the location of the lat/long into states myself, and have that as an available dimension in my data?  This seems odd, since we have the polygons for the states already inside of tableau?

       

      It was super easy to get it to map points, but I can't figure out how to get it to let me select "filled map" in show me.  I promise that I've spent about an hour searching on google and in the forums, and have looked at all the examples.   Help?

       

      Let me know if you want an uploaded file - the one I'm working with is a bit on the big side (well, for me ~600MB), so, I'll need to edit the data down.

       

      tableau-dimensions.jpg   tableau-map.jpg

       

      --Seth

        • 1. Re: Using my own latitude/longitude for chloropleth (filled) maps?
          Andy Piper

          Seth,

           

          Right now the filled maps work with specific geographic entities such as County, Zip and State. If you are able to include a field containing the state or zip data in your data set (it also needs to be recognized in Tableau as a valid Geographic Data field), select your state or zip and choose a filled map; with county you would need to include both county and state within two separate fields.

           

          Tableau does not have reverse geocoding functionality, so it is unaware of the details about a particular set of coordinates. If you need reverse geocoding assistance to determine zip or state, consider going to http://www.findlatitudeandlongitude.com/batch-reverse-geocode/#.UL34C4Ygisx to look up the nearest address to the coordinates provided (this is a free site, though it may have limits to the amount it will allow you to process).

           

          If you are adding the filled map to go behind the existing points, place a second copy of your latitude field on the Rows shelf. Click the down arrow on the Marks shelf, and select Multiple Mark Types. Where it indicates "All", click the right arrow until you come across the second instance of your latitude field. Move the Zip or State field to the level of detail shelf (if using county level info to populate the map, you would need both county and state fields), then change the mark type to Filled Map. To have the filled map appear behind the existing points, right click on your second latitude field on the rows shelf and select Dual Axis.

           

          Hope this helps,

           

          Andy

          1 of 1 people found this helpful
          • 2. Re: Using my own latitude/longitude for chloropleth (filled) maps?
            Seth Redmore

            You're awesome!  Thank muchly.

             

            I've found that my primary data source (DataSift), actually transforms the lat/long into city/state- I just need to snarf and split that field (which I hadn't done with my original dataset).

             

            Got a new download of my dataset going, and we'll see how this new set works.

             

            Thanks again.

            --Seth