4 Replies Latest reply on Aug 30, 2018 1:46 PM by Barata Ribs

    Multiple measures from different datasources in the same plot

    Barata Ribs

      Hello community, after running out of ideas I come to you.


      A little background of the problem: I have wind turbines that produce an output (Output1) depending on the wind speed (Measure1). I have a logger that is continuously recording the measured wind speed (Measure1) and the actual output (Output1) every 10 minutes, this data is stored in a SQL database and I can´t change that.


      The turbines have an expected output (ExpOutput) depending on the wind speed (Measure1calculated). In engineering that´s also called a power curve, reflecting the expected power produced by the machine depending on the input (wind). The power curve, or expected behaviour, is also stored in a SQL database even though it´s static information.


      I must keep my data in a SQL format, can´t change that.


      I have two objectives:

      1. Plot a scatter of the machine behaviour (Measure 1 X Output 1)

      2. In this same plot, plot the expected output (Measure1calculated X ExpOutput)


      I managed to produce the first plot defining Output1 and Measure 1 as dimensions, but I can´t manage to plot the expected behavior in the same plot.


      Any thoughts?


      Below a picture of my expected chart (easily done in Excel) and I attached a workbook with samples.

        • 1. Re: Concept issue
          Mavis Liu

          Hi Barata,


          Please could you include the third measure in the workbook?


          You can create one combined axis chart and then a dual axis chart.


          It'll be something like this (but the data I have has more points):




          Thanks and please see the attached workbook.



          • 2. Re: Concept issue
            Barata Ribs

            Hi Mavis, thanks for taking the time.

            I´m not sure I understand what you mean with "third measure". There´s one real measure (measure 1) and one output (Output1).

            In that workbook, you can also find the theoretical behavior, which is one measure and one output.


            Did that help?

            • 3. Re: Concept issue

              Barata and Mavis,

              Sorry for jumping in.

              Just wanted to throw out another suggestion.


              If you have control over the headers of your datasources,

              it may work easier if you could rename the ones in Expected

              to match the ones in Behavior. Then you could union the two sheets

              and plot one field against the other.

              (That is, if your datasource type allows: Union Your Data

              This can also be done in Tableau Prep)


              If you are not able to change those, you can still union them

              but then create a unioned Measure1 using:

              IF ISNULL([Measure1Expected]) THEN [Measure1Behavior]

              ELSE [Measure1Expected]



              Similarly for Output.


              Then you can plot unionedMeasure1 vs unionedOutput

              and put the [Table Name] field created by the Union

              on the Color shelf.


              You can then make the line as a dual axis with

              [Output1Expected] on the Rows shelf and [Measure1Expected]

              on the Path shelf.


              Please see workbook v2018.1 attached in the Forum Thread.



              • 4. Re: Concept issue
                Barata Ribs

                Nice workaround swaroop, thanks for contributing!