6 Replies Latest reply on Apr 8, 2013 7:00 AM by Jonathan Drummey

    Create a Variable using previous information of itself.

    Andres Castaneda

      Dear all,


      I need to create a variable that uses previous information of itself and information from other variable at the same time. This is a small example using Excel in which I create variable Y using the following logic:

       

      The first observation of variable Y (let’s call it Y1) is equal to the first observation of variable Z (Z1) which is constant over the time. The second observation of Y has the following form: Y2 = Y1*a + X2, where “a” is parameter and X2 is the second observation of variable X. Subsequently, the third observation of Y will be Y3 = Y2*a+X3… and so on.

       

      The question is simple, how I can construct variable Y in Tableau? I have tried several ways with no success. The following table is an example of the desired Y variable and the file has the very same information if you require more clarity.

       

      Yvar.PNG

       

       

      Thank you so much for your help.

       

       

      Andres.