Removing NaN from form

User Support Form Building
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1

Hello.
Is there a way to remove the ‘NaN’ text that appears in calculated fields until a number is entered? Can it just appear blank (or some other label) until the other fields are populated to create a calculation?
the ‘NaN’ is confusing people completing the survey.

Thank you

2

Any arithmetic calculation expression that consumes fields which may be (initially or otherwise) blank must explicitly interpret blanks as 0, otherwise you will get “NaN”. See https://docs.opendatakit.org/form-logic/#empty-values-in-math for prescribed solution.

1 Like
3

Hi. I tried both examples from the link you provided, but both caused ‘NaN’ to appear twice instead of once. I replaced potentially_empty_value with my variable.
I tried
if(${potentially_empty_value}="", 0, ${potentially_empty_value})
and
coalesce(${potentially_empty_value}, 0)

but neither worked. They belong in the calculation column, correct?

Thanks

4

can you post the original form with the calculated field that you are having a problem with?