How to create geojson Polygons from Lines?

Question

Given a series of overlapping lines (MultiLineString) in Geojson how can I create polygons for those portions that form an enclosed a space?

Sample data - https://gist.github.com/maphew/7bb77059574ea714977edae41e4b114c

Operational environment is web browser and/or a server with Node.js. Desktop tools such as ArcGIS and QGIS are not available. Connection to a remote service API is acceptable but prefer to avoid. (Following principle of minimizing external dependencies.)

This is my first significant foray into javascript-land, some hand-holding may be needed. ;-)

What hasn't worked

Seeing OGR DXF Closed Polyline Conversion I tried to filter the geojson through DXF to shapefile polygons using command line ogr2ogr (v2.2.0). Thinking if I could get it to work there I could replicate in node-gdal. A polygon shapefile is created but it has no features. -skipfailures didn't help.

Related https://gis.stackexchange.com/questions/58245/generate-polygons-from-a-set-of-intersecting-lines — matt wilkie, Jun 25 '17 at 03:53
I suppose you had better to use a ready solution to create polygons. For example PostGIS ST_Polygonize and ST_node or GRASS GIS. — Zoltan, Jun 25 '17 at 11:58
There is a node module - turf/linestring-to-polygon which might do the trick. If you want to do it all in the browser then You can probably implement the algorithm described here using turf. (docs). — RoperMaps, Jun 26 '17 at 08:35
Thanks @RoperMaps. Turf/linestring-to-polyon doesn't work, but in Turf I found another module, less than 1 month old, called Turf/polygonize. It reads like it should work, but doesn't. I filed a bug, hopefully it gets fixed soon. :-) — matt wilkie, Jun 27 '17 at 19:44

How to create geojson Polygons from Lines?

What hasn't worked

0 Answers0