Screen out participants BMI (2) | XM Community
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Screen out participants BMI (2)

  • 29 October 2018
  • 6 replies
  • 248 views
L
Hi,

last week I asked your help to screen out participants based on their BMI (kilograms/centimeters).
I now want to add screening based on BMI in terms of Feet-Inches and pounds.

Somehow my formula doesn't work.
Can anyone help my find the error I made?
I have three text entry items (content validation : number)
The formula and survey flow are attached.

Thank you!
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Best answer by TomG 29 October 2018, 21:06

View original

6 replies

L
I can see that it is an invalid expression.
L
I tried it with a new formula, which seems to be valid.
However, it still doesn't show the calculation of BMIP and it appears that even though I fill in the questions they are registered as if there were not displayed.
L
Ok, i have been working on it all day and I now know where my problem is:

My problem is with the BMI based on feet-inches and pounds (BMIP).

First: BMIK (centimeters and kilograms) is going fine:
formula BMIK: (x/ (( y/100)*(y/100)))
and
formula embedded data BMIK:
$e{ ( q://QID5/ChoiceTextEntryValue ) / ( ( ( q://QID4/ChoiceTextEntryValue ) / 100 ) * ( ( q://QID4/ChoiceTextEntryValue ) / 100 ) ) }


Also, the formula for BMIP is fine: I can see that it calculates the right numbers for BMIP:
based on the formula BMIP: ((x/(((y*12)+z)^2))*703)

But then the problem is with the formula for embedded data....the embedded data of BMIP all show 0 zero, so this does not match the formula somehow.
$e{ ( ( q://QID3/ChoiceTextEntryValue )/ ( ( ( ( q://QID1/ChoiceGroup/SelectedChoices ) * 12 ) + (q://QID2/ChoiceGroup/SelectedChoices ) )^ 2 ) * 703) }

Can anyone see the error maybe?
Akdashboard
Rank
Userlevel 7
Badge +6
@Loes
Doing a quick look at your BMIP formula, and it looks like you are missing spaces before and after 12 for QID50 and after the QID51 multiplication sign.


It should read (with some short hand) q://QUID52 / ( ( ( QID50 * 12 ) + QID51 ) * ( ( ( QID50 * 12 ) + QID51 ) ) ) * 703 )

Note - I tried to bold or underline the spaces, but it formatted poorly.
TomG
Rank
Userlevel 7
Badge +27
I think it should be:
```
$e{ ( ( q://QID3/ChoiceTextEntryValue ) / ( ( ( ( q://QID1/ChoiceGroup/SelectedChoices ) * 12 ) + ( q://QID2/ChoiceGroup/SelectedChoices ) ) ^ 2 ) * 703) }
```
I added three spaces:
1. between q://QID3/ChoiceTextEntryValue ) and /
2. between ( and q://QID2/ChoiceGroup/SelectedChoices
3. between ) and ^
L
Thank you! It worked like this:

(x/(((y*12)+z)^2))*703

$e{ ( q://QID3/ChoiceTextEntryValue ) / ( ( ( ( q://QID1/ChoiceTextEntryValue ) * 12 ) + ( q://QID2/ChoiceTextEntryValue ) ) ^ 2 ) * 703 }

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