the sample I posted also do a simple prediction only on past data using a linear trend.
That's just a very simple example, of course.
Have you already an idea how you could make a prediction (e.g. linear, average, polynomial (these are already offered by QV as trendlines).
There are also some statistical functions offered by QV to calculate your prediction data "manually", please look into the statistical aggregation functions (AFAIR mostly for linear regression).
If you need advanced prediction you might want to consider doing this outside the QV scope maybe using R (though I think there is an ongoing integration with R and QV, you need to check out).
