Trendline using linest_ function within a range

[anandathome]

Hi Experts,

     I have the following data:

MonthYear	SalesQty
Jan-13	10000
Feb-13	11000
Mar-13	15000
Apr-13	8500
May-13	0
Jun-13	0
Jul-13	0
Aug-13	0
Sep-13	0
Oct-13	0
Nov-13	0
Dec-13	0

I am using the following expression to get trendline:

LINEST_M(TOTAL aggr(sum(SalesQty),MonthYear),MonthYear)*MonthYear + linest_b(total aggr(sum(SalesQty),MonthYear),MonthYear)

This takes even the zero values of salesqty and plot the trend (which give not the very best trend).

Is is possible to specify in linest_m and linest_b function to take only the range from Jan-2013 to April-2013 into account for plotting the trendline?

OR

If there is any other way, please answer.

[anandathome]

Hi Everyone,

     I could not find any solution on any other discussion.

Could anyone please help me on this?

I basically want linest_m function to use only a limited time period to project the trendline.

The red-dotted line gives the forecast using linest_m and linest_b function

Expression as:

=LINEST_M(TOTAL aggr(sum(OrderQty),YearMonth),YearMonth)* YearMonth

+ linest_b(total aggr(sum(OrderQty),YearMonth),YearMonth)

Is there any way I can ask the linest_m and linest_b function to use the values from 201204 to 201303 to use as history and project the trendline?

[anandathome · Accepted solution]

I found something helpful on the post:

http://community.qlik.com/thread/53721

and this solves my problem.

Thanks to dtalbot777