4 Replies Latest reply on Jun 19, 2018 2:44 AM by Farshad Rastgouy

    Dynamic colour scheme for different parameter selections?

    Farshad Rastgouy

      Hi there,

       

      I've created a parameter so that I can choose from a list what information I am displaying on my viz. I am displaying how a "measure" is different on different regions of a map with the use of colour. The number distributions are different for the different measures represented on the parameter selections. Thus, I need to centre the colour schemes at different values for the different parameter selections.

       

      This is problematic, because you can only pick one colour scheme and centre value for an entire list of parameter selections on Tableau.

       

      The closest I have managed to get is specifying different single colours for the different parameter selections by duplicating the longitude on a dual axis and then applying the parameter to the colour scheme. This gives me two longitude tabs on the marks card, which means that I can select different single colours for different parameter selections. This is not useful, however, as I need the colours to change according to changing values of measure.

       

      (This is the closest I have been able to get)

      tableau.PNG

       

      tableau2.PNG

       

      Can anybody help me with this?

       

      Here is the link to the viz: https://public.tableau.com/views/Impactofvolcanoesonhumanssince1750/Sheet24?:embed=y&:display_count=yes&publish=yes

      https://public.tableau.com/views/Impactofvolcanoesonhumanssince1750/Sheet24?:embed=y&:display_count=yes&publish=yes

      Data Source:

      https://www.ngdc.noaa.gov/nndc/struts/form?t=102557&s=50&d=50

       

      Thanks,

      Farshad

        • 1. Re: Dynamic colour scheme for different parameter selections?
          Don Wise

          Hi Farshad,

           

          Please see newly uploaded workbook on Tableau Public: Tableau Public

           

          Here's what I did to get there:

           

          Created Map Parameters

          Screen Shot 2018-06-09 at 2.53.32 PM.png

          Calculation to change orientation display to where Deaths, Injuries, Homes Destroyed or Eruptions occurred by Lat/Lon:

          Screen Shot 2018-06-09 at 2.53.56 PM.png

          Calculation to change color upon parameter change (then each color was independently changed under COLOR marks card):

          Screen Shot 2018-06-09 at 2.54.06 PM.png

          Finally, a Viz-in-ToolTips to show summary of all related datum by Lat/Lon:

          Screen Shot 2018-06-09 at 2.54.23 PM.png

          Hope that works out for ya! Don

          • 2. Re: Dynamic colour scheme for different parameter selections?
            Farshad Rastgouy

            Hello again Don ,

             

            Thanks a lot for your help!

             

            I want to use create a viz whereby you can tell how many people died, or how many eruptions there have been by looking at the colour. The problem with this though is that the range of numbers is pretty extreme considering the distribution of numbers.

             

            For example, the maximum death toll is almost 30,000 for volcanoes, but most volcanoes won't have a death toll of more than a couple hundred. This means that the colour distribution is very one-sided; you tend to see a lot of one colour but very little of another.

             

            What's more is that, if you want to get a good colour distribution, you need to centre the colour scheme under the "advanced" settings at different values. But on Tableau, if you were to go into the "advanced" settings and set the centred valued at say 500 for death toll on a "diverging" colour pallette, it would then centre the colour scheme at 500 for everything (number of eruptions, number of houses destroyed, etc).

             

            I don't know how to centre the colour scheme of different parameter choices at different values. This is the problem.

             

            Thanks,

            Farshad

            • 3. Re: Dynamic colour scheme for different parameter selections?
              Don Wise

              Hi Farshad,

               

              This'll be my last post until Monday But I believe I got you closer to your goal. 

               

              Please check out the most recent upload I just made to Tableau Public. What you gain in this update is that the measures are dynamically coloring based on the range of color and range of values (I used temperature diverging 5-steps but feel free to pick another color) ; however, what you lose in this is that each category (Deaths, Injuries, etc.) will now be that particular color range. 

               

              They cannot have their own individual colors and ranges; I've already been down that road with using individual color legends per measure and they work well with tables of data, but not on a map, nor have I seen anyone else get to that on a map! 

               

              The parameter control works the same as before.  This was done by dragging the Parameter Control to Colors on the Marks Card.  Cool trick!

               

              Please see below example - have fun!  Thx, Don

               

              Screen_Shot_2018-06-09_at_6_34_19_PM.png

              • 4. Re: Dynamic colour scheme for different parameter selections?
                Farshad Rastgouy

                Hi Don,

                 

                Thanks for filling me in this limitation and helping me work my way around it.

                 

                I've decided to not use a parameter for maps as I can't adjust the colour scheme according to the different maps.

                 

                Thanks a lot for you help again Don!

                 

                Farshad