0 Replies Latest reply on Oct 17, 2013 1:13 PM by ben kwok

    single factor polynomial trend line possible?

    ben kwok

      Tableau only allows trend lines (scatter plot) with a minimum of 2 factor polynomials.  I typically generate single factor polynomials (y = ax^b).  am I just out of luck here?

       

      here is my scenario.  we generate equations to predict Y. I want to show how new data plots against that equation.  I want to display that equation via a trend line.  so what I do is add a calculation to my measure that models that equation and then I make a 2 factor polynomial trend line to go through it.  then I hide the marks so it looks like a nice curved line.  This is technically not accurate as my equation is a single polynomial equation.  Most of the time I find this is close but not exact.  it also depends a lot on how much "new data" I have to plot against the equation.  if I have a lot, it looks nice, but if I only have a few data points the 2 polynomial trend line looks awful.