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Your LimeSurvey version: LimeSurvey Community Edition   Version 6.4.0+231218 
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Survey theme/template: Custom theme based on Bootswatch
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I have a number of computations within a survey that look like:
round(sum( HM1.value  +  HM2.value  +  HM3.value  +  HM4.value  +  HM5.value  +  HM6.value  +  HM7.value  +  HM8.value ) / 8, 2)

However, each of the questions (HM1...HM8) includes an answer option of N/A. The value for N/A = 0. The denominator needs to be a variable based on the number of non-zero responses. For example, if HM1.value == 0 and all of the other questions are non-zero, the denominator would be 7 (not .

I need to do this for ten (10) subscales that have 4 to 8 questions each.

Is is possible to create a variable for the denominator in the equation?

Many thanks!

dave
 

You can use 
{countif("0",HM1.value, HM2.value,...)} to get the number of N/A,
or
{countifop(">","0",HM1.value,...)}
to get the number of "not N/A".

So at the end you will have somthing like 
{round(sum(....) / countifop(...),2)}

Joffm

Fantastic! Here's what I have for this question:
round(sum(HM1.value + HM2.value + HM3.value + HM4.value + HM5.value + HM6.value + HM7.value + HM8.value) / countifop(">", "0", HM1.value, HM2.value, HM3.value, HM4.value, HM5.value, HM6.value, HM7.value, HM8.value), 2)

I'll test to confirm.

I hope it was a typo.
It's sum(a,b,c,..)
not sum(a+b+c+...)

Joffm 

Yikes! I've been using sum(a+b+c+...) forever!

And you know what you were doing?
First you do an addition
"a+b+c" with a result "d".
Then you use the sum-function to "sum(d)".
So one part is obsolet.

Joffm

round(sum(HM1.value, HM2.value, HM3.value, HM4.value, HM5.value, HM6.value, HM7.value, HM8.value, HP1.value, HP2.value, HP3.value, HP4.value, HP5.value, HP6.value, HP7.value, HP8.value) / countifop(">", "0", HM1.value, HM2.value, HM3.value, HM4.value, HM5.value, HM6.value, HM7.value, HM8.value, HP1.value, HP2.value, HP3.value, HP4.value, HP5.value, HP6.value, HP7.value, HP8.value), 2)

Works perfectly! Thank you!