Error in Enketo when calculating distance from a geotrace

[it_emm_jos]

Hi, thanks again for your help

We collect data on ODK Collect (version 2022.1.2) and use Enketo on KoboToolBox to modify the submissions.

On the form, we have 6 parcels in a submission and for each parcel we take a geotrace. From the geotrace, it calculates the distance.
The distance is calculated for the 6 parcels on ODK.
It works for 5 parcels only on Enketo: for the last one the distance is NaN whereas it should be calculated.

For the parcel with the error, the geotrace is well defined.

Thanks,
Emma

[Kal_Lam]

Hi @it_emm_jos, so you mean, it works fine with the Collect android app but is an issue with Enketo?

@it_emm_jos

The distance is calculated for the 6 parcels on ODK.

[it_emm_jos]

Hi, thanks you for your answer.
Yes exactly: it works well on ODK Android App but for 5 parcels out of 6 only on Enketo.

Emma

[Kal_Lam]

@it_emm_jos, I don’t know if this should help but would you mind having a look at our previously discussed post:

GPS lines: measuring distance in real-time

Welcome back to the community, @rratnaya! I don’t think this is possible, but I am leaving this open to the community to chime in the discussion. However, at the same time, I am also sharing the xlsform to demonstrate how distance can be calculated in KoBoToolbox using geopoint and geotrace. Maybe it should be helpful to those, who wish to measure distance in their project(s). In the survey tab of your xlsform: [Image 1] Reference xlsform: Calculating Length.xls (29.5 KB)

Maybe it should give you some clue to solve your issue. I tried this with Enketo and it worked for me though.

[it_emm_jos]

Thanks!
The solution is actually that Enkêto duplicates some GPS points.
When deleting duplicated points, the distance calculation works well.

Emma

[Kal_Lam]

Thank you, @it_emm_jos, for updating this with the entire community!

[wroos]

Hello @it_emm_jos,
If you think this is a bug in Enketo, could you, please, document it in detail (bug template) and with a reproducible example?
I remember some issues in the forum in the past concerning duplicates with geoshape.