Why did I use array formula - help

[Diddy]

Hi,

I used the following in a spreadsheet over a year ago and can't remember
how, why, or what I've done. Head spinning because I'm making unexpected
changes which were needed "Now, if not sooner"
The formula below is entered as an array formula but don't know why
{=IF(ISERROR(AVERAGE(IF(Score>0,Score))),"",AVERAGE(IF(Score>0,Score)))}
Named range "Score" is a dynamic range as below
=OFFSET('Sheet1'!$Q$1,0,0,COUNTA('Sheet1'!$Q$1:$Q$35),1).
If anyone can help I would be grateful

Cheers
Diddy

 

[Luke M]

You are doing the equivalent of an "averageif" by having IF function sort
through your Score range and only outputting data that meets your criteria.
This is why you needed an array. The ISERROR is there in case you have zero
data points meeting criteria.

However, a shorter, non-array formula would be:
=IF(COUNTIF(Score,">0")=0,"",SUMIF(Score,">0")/COUNTIF(Score,">0"))

 

[Pete_UK]

You might have zero values in the range "score", and if so the normal
AVERAGE function would count these and give you a lower average. Hence
the AVERAGE(IF part of the formula which only counts values that are
above zero. There is further checking in the formula so that it only
returns an average (of above-zero items) as long as there are no
errors in the range (or indeed if all values are zero, so there is no
average to return).

It needs to be an array formula so that it can check each value in the
range to see that it is above zero.

Hope this helps.

Pete

 

[David Biddulph]

The reason for it being an array formula is that you want to apply the
IF(Score>0,Score) formula to each element of the Score array.

 

[Diddy]

Hi Luke,

Thanks for replying.
I've probably been helped with the formula by someone here.
The workbook works for different groups by hiding some rows using a macro.
So would the formula work to average only those cells in the range that have
a value. Hidden rows have zeros and shouldn't be included in the average.
If that is what it's doing could you help me by explaining how the formula
works please.

Many thanks
Diddy

 

[Diddy]

Hi Luke,

Many thanks for your reply

Please ignore previous post. When I stopped panicking and let the brain work
(it does sometimes), I realised that you had answered all the question

Thank you again and thanks for the alternative formula

Cheers
Diddy

 

[Diddy]

Many thanks
Diddy

The reason for it being an array formula is that you want to apply the
IF(Score>0,Score) formula to each element of the Score array.
--
David Biddulph




.

 

[Diddy]

Many thanks
Diddy

You might have zero values in the range "score", and if so the normal
AVERAGE function would count these and give you a lower average. Hence
the AVERAGE(IF part of the formula which only counts values that are
above zero. There is further checking in the formula so that it only
returns an average (of above-zero items) as long as there are no
errors in the range (or indeed if all values are zero, so there is no
average to return).

It needs to be an array formula so that it can check each value in the
range to see that it is above zero.

Hope this helps.

Pete



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