Comparing models out of the DCA Wrangler simple task if you are familiar with Axis.Columns feature in Spotfire. In this example, we’re going to take the cross table and use it to look for differences across columns.
Consider this scenario, we are creating declines of Teapot dome data in 2016 and then comparing them to 2017. We are specifically looking at the remaining reserves to see how much the reserves have changed based upon the new production data. Our resultant Autocast DCA data might look like this:
Here I’ve got an axis along the top, modelName, and a cell axis with my remainingReserves.oil column. I can’t compare these the way they are! Normally in custom expression language, I can call out columns but not “conditionally”-based upon the value. HOWEVER, I can compare across columns using the OVER command like we do in time series-styled visualizations.
This is done using the OVER command, constrained by “Previous([Axis.Columns])”. This tells Spotfire to walk backwards to the column to the left of it.