lineOffset returns NaN for some LineStrings

[mllava]

Hi,

I'm having an issue with lineOffset. Please see the example here: https://jsfiddle.net/y4xfzxmx/3/

For the given LineString, lineOffset returns NaN from coordinate 7 onwards, until one before last; even happens with distance = 0. It only happens with a few lineStrings that I'm working with.

Any clue why this could be happening?

Many thanks in advance!
Martin

[rowanwins]

Hi @mllava

Thanks for the report and the jsfiddle. Unfortunately the lineOffset is a little bit flimsy at the moment and in need of some love (I was blissfully unaware of a few complexities when I started work on it initially). I try and take a look over the next few days and report back my findings, although a proper fix is probably a little while away.

Cheers

[vamshi29292]

The coordinates of the points at 8th and 9th index are identical. What is the expected behaviour in this case? Should the duplicates be removed before processing? (That would make the number of points on the output feature and input feature not equal)

[rowanwins]

Ah that probably explains it, Thanks for chiming in @vamshi29292 . @turf/clean-coords can be used in this task.

[mllava]

Well spotted @vamshi29292 ! This flags an issue on my end! Thank you!