How to use calculate question in Kobotoolbox

[@OlajideAdedayo-q5s]

Great Job! Please how can one handle the case in which the respondence make no input to one of the variable in the calculation living it blank and the Calculation reads NAN

[@AdrisyaTech]

Thank you for your question. In your case you can use "if" function in calculate question. For an example you are calculating the waist hip ratio. You have 2 questions asking about waist circumference (variablename: waist) and about hip circumference (variable name: hip). If you want to display NAN when any of the waist or hip variables are empty and calculate waist hip ratio if both values are present then in that case use this formula:-
if(${waist}="" or ${hip}="","NAN", ${waist} div ${hip})
Once it is kept in the calculation section, name the variable as "waist_hip_ratio". In order to visualize the value add a note and call for the value of calculation with ${waist_hip_ratio}
I suggest you to make waist and hip both questions mandatory to prevent missing.

[@abdulchaba3188]

How do you add a constant figure in a formula on kobotoolbox? For example in the formula for body surface area (BSA)= Height (in cm)^0.42246 * Weight (in kg)^0.51456 * 0.0235

[@disciplineetimpact]

thanks !

[@AdrisyaTech]

You're welcome!

[@pradeepghimire8405]

Hello sir, can you help me design the some question repeat as per required, like if there are two member in family and no next section two separate input for these member of family detail input.

[@AdrisyaTech]

you can download the excel form and add repeat_count column where you can add ${total_family_member}. You can refer this forum.getodk.org/t/repeat-group-and-relevance/27530/2 Please message me in my viber [phone]) if needed further. I'm happy to help.

[@pradeepghimire8405]

@@AdrisyaTech thank you.