Need help on projections and I've tried and I did not get excited.
The problem is I want to make projections for the months of 2012, data from 2011 in one table, but I have no idea how I can do or apply a formula (Forecast), such as the trendline. I ask your help in this work.
If I understand your requirement then all you need to do to see your trendline extend beyond the current date is enter the properties for the chart, tick Forecast and specifiy how many months forward you wish to extend the line.
Looking at your chart though you will need to be careful with your dimension, as it only contains the month rather than year and month. This means that when you do get data for Ene 2012 it will get aggregated with Ene 2011. You should create a field for Mes Año created by doing the following in your load script:
Date(MonthStart(TimestampUTC), 'MMM-YY') as [Mes Año],
Since I made the changes recommended, but do not know how to apply it on the table?,as I can get the values of 2012? as I can see the number of the projection?
Hi there - as far as I'm aware you can not use the points that the trend line crosses to populate values in a table. Your best bet may be to put on a variable and a slider to uplift the 2011 values by a factor until the value for December 2011 matches the highest point on the trendline. The same factor could be used all previous months to give a feel for what the values could be for those months.
Would be interested to see anyone elses ideas on this.
I have also been trying to find a way to forecast in a "Table" chart. The way i have found is some what complicated and could be consolidated into 1 statement but i have split it out in my application to make life easier to follow.
The mathematical equation for how excel calculated it's forecasting is:
(slope) m = AVG((xy -AVG( xy)) / (avg(x))2 - avg(x2)
(Constant) c = AVG(y) - m * AVG(x)
(Value) y = mx + c
I'm no mathematician and that's all very nice but what do we do with that? (Thanks to my colleague who understands advanced maths, we can now use this in
a Qlikview table)
x = time periods this can be time period 1, 2,3 etc or it can be dates
y = Values that are in your table
I have attached a basic Qlikview document which shows how this is done.
