yogi_Compute in Android ROM Comparison Table Row By Row Average Of Numbers in Points Columns

                                         Google Spreadsheet   Post  #1559
Yogi Anand, D.Eng, P.E.      ANAND Enterprises LLC -- Rochester Hills MI     www.energyefficientbuild.com.   Mar-15-2014
post by Spon4ik (https://productforums.google.com/forum/#!category-topic/docs/spreadsheets/K4TN2b0nbEA)
Auto populate column with a Filter Formula

Hi all!

I need a help with function that will repeat each new row that inserted to the sheet, array function could help, but

the problem is in the FILTER() function

my sheet: NEW android ROM comparison

in sheet named sw, column D3:D must be a function, that calculates sum of cell values, in "points" named columns (each row separately), and divide by count of "points" columns

I can't just select in formula predefined columns and must use filter(), because every user can add a columns and also can add a new category so it also can add another one or more "points" columns - in this case the formula will not know about a new value place and will ignore it.

=SUM(FILTER(J3:CQ3,$J$2:$CQ$2=$L$2))/COUNTIF($2:$2,$L$2)

does the job, but I need to continuously copy this function every new row.

I've tried 

=ArrayFormula(SUM(FILTER(J3:CQ3,$J$2:$CQ$2=$L$2))/COUNTIF($2:$2,$L$2))

but it doesn't work.

can anyone suggest something?

thanks in advance

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