topic Re: Return the bearing of a polygon edge based on selection in Developers Questions

Return the bearing of a polygon edge based on selection using Arcade

Jake_S — Mon, 13 Sep 2021 22:29:40 GMT

Greetings folks,

Looking to be able to return the bearing of the side of a polygon based on a interaction.

I have a carto points feature class that I want to populate its F_ANGLE field with the bearing of the side in which intersects with a polygon. We use that bearing to change the symbology rotation. Any help would be great.

The image below shows a polygon and a point with symblogy interacting. I'd like to get the bearing of that intersection

I have got this working for an intersection of a line feature but not a polygon (image below).

Code for the intersection of lines is below, replacing the feature with a polygon does not work. Looking for someone with a bit more coding knowledge for some help

var LinesFC = Intersects(FeatureSetByName($datastore, "Lines", ['objectid', ''], false), $feature) if (Count(LinesFC) > 0) { var line = first(LinesFC) var geom = Geometry(line) var pt0 = geom.paths[0][0] var brg = Bearing(pt0, Geometry($feature)) if (brg > 90 && brg <= 360) { return (450 - brg) } return (90 - brg) } return null

Thanks in advanced.

-JS

Re: Return the bearing of a polygon edge based on selection

BillFox — Mon, 13 Sep 2021 22:27:05 GMT

Maybe something in this tool set Reporting COGO descriptions

Re: Return the bearing of a polygon edge based on selection using Arcade

JohannesLindner — Tue, 14 Sep 2021 06:42:04 GMT

var PolyFC =Intersects(FeatureSetByName($datastore, "gewaesserkataster_sde.GWK_SDE_ADMIN.poly"), $feature) // return early if no intersecting polygon is found // doing it this way saves you from indenting everything in your if block if(PolyFC == null || Count(PolyFC) == 0) { return null } // lines have the "paths" attribute, for polygons that's "rings" var poly = First(PolyFC) var geom = Geometry(poly) var pt0 = geom.rings[0][0] var brg = Bearing(pt0, Geometry($feature)) if (brg > 90 && brg <= 360) { return (450 - brg) } return (90 - brg) // if that works for you, cool. // I got really inconsistent results when testing this on irregular polygons, though, // so I'd go with something like this: var poly = First(PolyFC) var vertices = Geometry(poly).rings[0] var sr = Geometry(poly).spatialReference // loop through the vertices for(var r=0; r<Count(vertices)-1; r++) { // create a line segment between 2 adjacent vertices var p0 = vertices[r] var p1 = vertices[r+1] var line = Polyline({"paths": [[ [p0.x, p0.y], [p1.x, p1.y] ]], "spatialReference": sr}) // do nothing if $feature doesn't intersect that line segment if(Disjoint($feature, line)) { continue } // return the bearing of the line segment var brg = Bearing(p0, p1) if (brg > 90 && brg <= 360) { return (450 - brg) } return (90 - brg) } // if you land here, the feature intersects a polygon, but none of its edges return null

Re: Return the bearing of a polygon edge based on selection using Arcade

Jake_S — Tue, 14 Sep 2021 13:32:19 GMT

Thanks for your efforts here!!!!

Unfortunately the solutions you provided an error by the arcade compiler (see below line 3)

I have seen this error before. the solution was to get a count of the initial FeatureSetByName intersection as seen below in line #2. Yet still gets an error with the geometry statement.

Where are you testing this? I am implementing this as as an Attribute rule on a enterprise geodatabase frim ArcGIS Pro 2.6.6. I wonder if there is an difference in environments.

Again you are a gem!

Re: Return the bearing of a polygon edge based on selection using Arcade

JohannesLindner — Tue, 14 Sep 2021 13:38:53 GMT

Line 1: Try changing the boolean parameter (includeGeometry) to true.

https://developers.arcgis.com/arcade/function-reference/data_functions/#featuresetbyname

Re: Return the bearing of a polygon edge based on selection using Arcade

JohannesLindner — Tue, 14 Sep 2021 13:43:49 GMT

Also, I'm on 2.6.3, Enterprise GDB, so no big differences there.

Re: Return the bearing of a polygon edge based on selection using Arcade

Jake_S — Tue, 14 Sep 2021 14:50:33 GMT

Oh man how did I miss that!!! Genius. @JohannesLindner you are my hero! I saw the same issue with inconsistent results with the first code but the second is working as expected!