Thanks for the reply.
I have done a mock-up example of my question in this Tableau link. There is capital cost, and a running cost (energy cost). From these data pairs, I have created calculated fields of the net-present value (NPV) at 5, 10, 15, 25 & 50 years.
I would like to do a net-present value scatter plot on this cost-stream, with years on the x-axis and the NPV on the y-axis. Excel would have allowed me to plot the 5/10/15/25/50 NPV calculations as connected line scatter plots, but I cannot find a way of doing this.
Note my actual data set is much longer, with hundreds of capital cost/energy cost pairs.
Nick, thanks for the sample workbook. You talk about wanting "years on the x-axis" but I'm not seeing a "years" field. So what is it we should put on the x-axis? I suspect we could do a few contortion and extract years from the fields you have, but I'm also hesitant work through these calculation without knowing we're really going in the right direction.
If you could create the Excel viz you are trying to emulate and post at least a screen shot, then we'll better understand what you're trying to accomplish. Please use the same data to create the Excel viz as you provided in the Tableau workbook.
Thanks for your help. One problem is I want to calculate NPVs inside Tableau so I can adjust interest rates etc and see responses.
Because the capital cost & energy cost data isn't like on a year by year basis, I don't know how a "Years" field (while maybe required), would work to create to map against the capital & energy costs.
I have attached a screenshot of how I would do it in Excel, with a x-axis of 5,10,25,50 years on a connected-dot scatter plot. Even if I name 5YrNPV "5", and 10YrNPV "10" etc in Tableau it still won't accept it as a numerical x-axis data-set, so I'm out of ideas.