Problem with GPS shape and line modification in Enketo

[Kal_Lam]

@martijnr, i have sent you a private message which explains the following in details:

My observation while collecting a 4 point geoshape information using KoBoCollect android app:

• Noticed 5 points entered while collecting data through KoBoCollect android app.
• Noticed 6 points separated with a ; while collecting data through KoBoCollect android app.
• Noticed 6 dark points while editing the submission in Enketo.
• Noticed 6 points separated with a ; while viewing data downloaded in an xls format.

Maybe @Xiphware’s views and expertize could also be helpful. cc: @jnm

[Xiphware]

fyi, my expertize is vastly inferior to @martijnr’s on any matter relating to Enketo…

But I am, indeed, most curious to know the root of this problem too!

[fpageot]

Hi @martijnr , @Kal_Lam and @Xiphware ,
Thank you for taking a bit of your time for this problem !
I’ve reproduced the error and tried to take as many info as I could.

So this is what I have of my phone :

Then I’ve immediately downloaded the data from Kobo to XLS and got :
48.81420163186936 2.378957122564316 0.0 0.0;48.81329421655844 2.3803019151091576 0.0 0.0;48.812516387392996 2.378598041832447 0.0 0.0;48.8135615856475 2.377382330596447 0.0 0.0;48.81420163186936 2.378957122564316 0.0 0.0;
(with “;” at the end)

Then I went to editing mode with Enketo :
48.81420163186936 2.378957122564316 0.0 0.0;48.81329421655844 2.3803019151091576 0.0 0.0;48.812516387392996 2.378598041832447 0.0 0.0;48.8135615856475 2.377382330596447 0.0 0.0;48.81420163186936 2.378957122564316 0.0 0.0;

Then I’ve clicked on “close polygon” and got :
48.81420163186936 2.378957122564316 0 0;48.81329421655844 2.3803019151091576 0 0;48.812516387392996 2.378598041832447 0 0;48.8135615856475 2.377382330596447 0 0;48.81420163186936 2.378957122564316 0 0;48.81420163186936 2.378957122564316 0 0
(so without “;” at the end)

Finally I’ve downloaded the data again on XLS and got :
48.81420163186936 2.378957122564316 0 0;48.81329421655844 2.3803019151091576 0 0;48.812516387392996 2.378598041832447 0 0;48.8135615856475 2.377382330596447 0 0;48.81420163186936 2.378957122564316 0 0;48.81420163186936 2.378957122564316 0 0
(Still without “;” at the end)

Hope this help to understand where the problem comes from

Thank you

Fabien

[martijnr]

Thanks! As @Xiphware noted out-of-thread and @fpageot observed as well, the cause is an invalid geoshape (and geotrace) value. The trailing ; is the problem.

I did look at whether Enketo can build in tolerance for such a value but have concluded it would not be a good idea. So the solution is to:

1. report and fix the bug in Collect. I won’t do this because I haven’t actually tried to reproduce the issue in Collect myself. So please somebody else do this
2. removed the trailing ‘;’ for already submitted geoshape and geotrace data. I’m hoping KoBo has some mechanism to do this.

[Xiphware]

@martijnr

I did look at whether Enketo can build in tolerance for such a value but have concluded it would not be a good idea.

I agree. It’ll only mask serious problems elsewhere in the stack…

[Kal_Lam]

Zulip: https://chat.kobotoolbox.org/#narrow/stream/6-Support/topic/Collect.20generates.20invalid.20geoshape.2Fgeotrace