topic Re: How to convert polygon vertex to lat/lon in ArcGIS JavaScript Maps SDK Questions

How to convert polygon vertex to lat/lon

GeraldRowe — Thu, 13 Oct 2022 21:04:50 GMT

I am aware how to iterate through the graphic.geometry.rings to get each x/y coordinate. However, this yields massive numbers that are obviously not lat/lon values. I have found quite a few examples of people asking the same or very similar questions, but none seem to yield an actual lat/lon result. I only get something like the below for each vertex:

Array [ -12390508.031742427, 3819480.562610634 ]

Re: How to convert polygon vertex to lat/lon

ReneRubalcava — Thu, 13 Oct 2022 22:05:16 GMT

Assume those are WebMercator, so you can run the polygon through the webmercatorUtils first.

https://developers.arcgis.com/javascript/latest/api-reference/esri-geometry-support-webMercatorUtils.html#webMercatorToGeographic

Re: How to convert polygon vertex to lat/lon

GeraldRowe — Thu, 13 Oct 2022 22:20:00 GMT

Thanks a million for this!

I spent an entire trying to figure out how to get these converted.

var geo = webMercatorUtils.xyToLngLat(graphic.geometry.rings[i][p][0], graphic.geometry.rings[i][p][1]);

console.log("Lon: "+ geo[0] +", Lat: "+ geo[1]);

Re: How to convert polygon vertex to lat/lon

ReneRubalcava — Fri, 14 Oct 2022 01:51:47 GMT

You could do the whole thing first too

const latLonPolygonGeometry = webMercatorUtils.webMercatorToGeographic(graphic.goemetry);

Then go over the rings.

Lots of options!