Inverse Exponential lines for a forecast are not mirrored
Hello!
I am making 2 line chart objects that are inverses on one another. One is usage type A, % of total usage. The other is usage type B, % of total usage. Usage A + B = Total Usage. One is going up as the other goes down.
Within the Expressions tab, I have trendline 'Exponential' selected. Within the Axes tab, I have Forecast checked with the value of 36 entered (months). My X-Axis is year-months.
My question is, why are the exponential trend lines in the forecast area of the charts not mirror images? The increasing trend line looks like a normal trend line but the decreasing trend line looks like a straight linear trend line and is not nearly as pronounced.
My Actual value lines are mirror images and I checked that the data and my formulas are correct. Is this something to do with the Trendline formula going down?
Please note I have advanced Excel skills but am very new to Qlikview. Thank you for the help in advance.
