Compare with last known value with gaps in time flow
Hello. I have one data set with products, dates, and unit prices. I'm trying to find the % difference in unit price between the current value and last known price for that same item. It'd have been easy if there had been a price for each consecutive month, but I may have a price for one month, yet, no price for several following months. I attached a picture of what I am trying to get (i.e. the yellow highlighted column and the arrows indicate where the months break the sequence and jump ahead causing me the problem to use the typical %difference formula in Spotfire). I really appreciate any help/guidance you could provide. Best.