topic Re: Lat/Long unit conversion with Arcade in Developers Questions

Lat/Long unit conversion with Arcade

AhjungKim4 — Thu, 11 Oct 2018 20:10:41 GMT

I am adding geometry fields using Arcade Geometry($feature).x and Geometry($feature).y. Since my target feature layer is in Web Mercator projection, my custom lat & long fields are displaying the values in meter. Is there a way to convert this to decimal degrees with arcade function?

Re: Lat/Long unit conversion with Arcade

XanderBakker — Sat, 11 Dec 2021 10:14:30 GMT

Yes you can. If you use the function below you will be able to convert the Web Mercator Auxiliary Sphere coordinates into Lat and Long (WGS 1984):

function MetersToLatLon(x, y) {
    // Converts XY point from Spherical Mercator EPSG:900913 to lat/lon in WGS84 Datum
    // Fuente: http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/
    var originShift = 2.0 * PI * 6378137.0 / 2.0;

    var lon = (x / originShift) * 180.0;
    var lat = (y / originShift) * 180.0;

    lat = 180.0 / PI * (2.0 * Atan( Exp( lat * PI / 180.0)) - PI / 2.0);
    return [lat, lon];
}‍‍‍‍‍‍‍‍‍‍‍

Below you can see it in action:

function MetersToLatLon(x, y) {
    // Converts XY point from Spherical Mercator EPSG:900913 to lat/lon in WGS84 Datum
     // Fuente: http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/
    var originShift = 2.0 * PI * 6378137.0 / 2.0;

    var lon = (x / originShift) * 180.0;
    var lat = (y / originShift) * 180.0;

    lat = 180.0 / PI * (2.0 * Atan( Exp( lat * PI / 180.0)) - PI / 2.0);
    return [lat, lon];
}

function CreateWazeURL(lat, lon) {
    return "https://waze.com/ul?ll=" + lat + "," + lon + "&navigate=yes"
}

var latlon = MetersToLatLon(Geometry($feature).X, Geometry($feature).Y);
var url = CreateWazeURL(latlon[0], latlon[1]);
return url;‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

In this case you have two functions: MetersToLatLon (lines 1 - 11) for converting web merc into lat lon, the CreateWazeURL function (lines 13 to 15) for creating a navigation URL based on lat and lon.

The actual code starts on line 17 where a list is created containing the lat and lon converted from the X and Y extracted from the geometry.

On line 18 the lat and lon values are passed to the CreateWazeURL function and the URL that is returned from the function is returned as result.

Some images to explain the result can be found here: https://community.esri.com/docs/DOC-11541-crear-un-enlace-para-navegar-con-waze-en-la-ventana-emergente-con-arcade (Spanish content)

Re: Lat/Long unit conversion with Arcade

AhjungKim4 — Mon, 22 Oct 2018 16:21:33 GMT

This works beautifully, thank you!

Re: Lat/Long unit conversion with Arcade

XanderBakker — Mon, 22 Oct 2018 16:28:31 GMT

Glad it worked!

Re: Lat/Long unit conversion with Arcade

Anonymous User — Thu, 31 Jan 2019 22:25:32 GMT

Hi Xander, thank you for your post this is very useful!!

Also - I was wondering if you had some ideas on how we could run a similar conversion to get USNG coordinates instead?

Thanks again,

Alix

Re: Lat/Long unit conversion with Arcade

XanderBakker — Fri, 01 Feb 2019 01:29:49 GMT

Unfortunately I don't. If you have access to the formula required I guess it would be possible to implement it in a similar way. I guess we have to wait until the projection engine is supported and available in Arcade to do this kind of transformation.

Re: Lat/Long unit conversion with Arcade

Anonymous User — Sun, 03 Feb 2019 02:24:46 GMT

Thank you Xander. Do you know where it would be possible to find a list of the projection engines supported and available in Arcade? I'm wondering if maybe MGRS may be in there instead...

Re: Lat/Long unit conversion with Arcade

XanderBakker — Sun, 03 Feb 2019 15:32:46 GMT

The point is there there is no support for projecting data inside an Arcade expression at this moment. Hopefully it will come soon. The only "projections" that you can currently do are the ones that you have a formula for and can translate to Arcade.

Re: Lat/Long unit conversion with Arcade

Raul_Jimenez — Sat, 11 Dec 2021 10:14:33 GMT

Thanks Xander Bakker‌, I have used your code to create a Google Street View link:

var p = Centroid( $feature )

function MetersToLatLon(x, y) {
    // Converts XY point from Spherical Mercator EPSG:900913 to lat/lon in WGS84 Datum
    // Fuente: http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/
    var originShift = 2.0 * PI * 6378137.0 / 2.0;

    var lon = (x / originShift) * 180.0;
    var lat = (y / originShift) * 180.0;

    lat = 180.0 / PI * (2.0 * Atan( Exp( lat * PI / 180.0)) - PI / 2.0);
    return [lat, lon];
}

function CreateGoogleStreetView(lat, lon) {
    return "https://www.google.com/maps/@?api=1&map_action=pano&viewpoint=" + lat + "," + lon;
    
}

var latlon = MetersToLatLon(p.x, p.y)
var url = CreateGoogleStreetView(latlon[0],latlon[1])
return url‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Thanks!

Re: Lat/Long unit conversion with Arcade

XanderBakker — Tue, 16 Jul 2019 12:40:42 GMT

Hola Raúl Jiménez Ortega ,

I have a related document here in Spanish about creating a Street View link:

https://community.esri.com/docs/DOC-10883-crear-un-enlace-a-streetview-en-la-ventana-emergente-con-arcade

More on Arcade in our GeoDev section that we are starting to build:

https://community.esri.com/groups/esricol-community/content?filterID=contentstatus%5Bpublished%5D~category%5Bgeodev%5D

Re: Lat/Long unit conversion with Arcade

TylerDeBruin — Mon, 01 Feb 2021 22:29:29 GMT

Is there an arcade code similar to this to show easting/westing?

Re: Lat/Long unit conversion with Arcade

AbiDhakal — Thu, 23 Feb 2023 16:16:51 GMT

@XanderBakker

Hey Xander,

I have a point feature federated service in UTM NAD83 Zone16. And, I have an x and a y column that I want to populate in decimal degrees using arcade. Is it possible? What do I need to do? Here is my email address, Xander: abi.dhakal@forestry.alabama.gov

Thank you,
Abi

Re: Lat/Long unit conversion with Arcade

BrittanyBurson — Thu, 23 Mar 2023 18:06:41 GMT

@XanderBakker also looking to convert from CA State plane zone 6 NAD83 into decimal degrees... all the examples I'm finding online seem to be converting from the default Web Mercator. Not sure it is possible.

Re: Lat/Long unit conversion with Arcade

MarceloCatalão — Thu, 22 Jun 2023 15:41:23 GMT

hello, I tried to use this function, but it gave an error when testing, I wanted the fields of the layer to automatically have the coordinates

thanks

Re: Lat/Long unit conversion with Arcade

JoseSernaUDC — Fri, 29 Sep 2023 21:40:35 GMT

@XanderBakker how are you determining the value "6378137.0"?

I am trying to use this NICE! Function you created but I think I am missing this portion.

Im trying to convert x/y NAD83 New Jersey State Plane(EPSG:3424) coordinates to WGS84(EPSG:4326)

here is an example of the x/y coordinates:

x = 570384, y= 475445

I should get the following in lat/lon

-74.2201199 (long), 40.13836 (lat)

Re: Lat/Long unit conversion with Arcade

LayerItOn — Thu, 30 Nov 2023 18:47:43 GMT

Is there any way to make this into an attribute rule?

Re: Lat/Long unit conversion with Arcade

AislinnCampbell — Tue, 09 Jan 2024 17:59:31 GMT

Did you get a response to this or find a solution? I need the same.

Re: Lat/Long unit conversion with Arcade

MarielaDel_Rio1 — Thu, 25 Apr 2024 18:58:48 GMT

I am not entirely clear on the formula.

I imagine the constant (6378137.0) is the semimajor axis, but why multiply by 2 and divide by 2? Doesn't that produce the same? could it be power instead of multiplication?

Re: Lat/Long unit conversion with Arcade

RyanBohan — Wed, 22 May 2024 21:43:07 GMT

Thank you! I had a Rest endpoint with only x,y in the attributes.

Your arcade worked perfectly to be able to use google directions

var x = Geometry($feature).x

var y = Geometry($feature).y

// Converts XY point from Spherical Mercator EPSG:900913 to lat/lon in WGS84 Datum

// Fuente: http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/

var originShift = 2.0 * PI * 6378137.0 / 2.0;

var lon = (x / originShift) * 180.0;

var lat = (y / originShift) * 180.0;

lat = 180.0 / PI * (2.0 * Atan( Exp( lat * PI / 180.0)) - PI / 2.0);

//return [lat, lon];

var string = "https://www.google.com/maps/dir/?api=1&destination=" + lat + "," + lon + "&tavelmode=walking"

return string

Re: Lat/Long unit conversion with Arcade

RyanBohan — Wed, 22 May 2024 22:26:54 GMT

It would be great to have some increased functions added to arcade to include ToLatitude(geometry($feature).x) and ToLongitude(geometry($feature).y)

Please consider adding a kudo to this idea

Covert point geometry to Latitude and Longitude - Esri Community