I want to forecast the amount of orders for the coming months. I've created a master calendar which adds dates for + 1 year after the max date in the data (so that I can forecast multiple months ahead).
However, the linest_m and linest_b aren't calculating the correct numbers.
To calculate the forecast I'm using the following functions:
(LINEST_M( TOTAL Aggr(Count([Werkorder partner]), [Maand melding]), [Maand melding]) * NUM([Maand melding]) )+
LINEST_B(TOTAL Aggr(Count([Werkorder partner]), [Maand melding]), [Maand melding])
As you can see the X is 72,30, when I calculate it manually however I get: 903 / 8 = 112,875 and B -111,875.
I've tried forcing the graph to start in (0,0) with
(LINEST_M( TOTAL Aggr(Count([Werkorder partner]), [Maand melding]), [Maand melding],0,0)
but this returns x as 6945,5948???
The correct formula (I think) should be: 112,875X - 111,875. Just have to get qlik to understand that
Okay got the linear regression correct, as in equal to the one qlikview calculates. But I still think the regression should be 112,875X - 111,875 not 72,30x + 150,44 as qlikview calculates. I think this has to do with the fact that a count of the orders in january returns null, as well as okt nov dec.