topic Re: How to use attribute rules to get nearest neighbors distance? in ArcGIS Pro Questions

How to use attribute rules to get nearest neighbors distance?

phess_luckstone — Thu, 18 Aug 2022 19:38:21 GMT

I am trying to use attribute rules to write in the distance to a nearest neighbor, I've been able to get the nearest neighbors name to show up, however the distance alludes me. Here is the code I was using, however when add an area it seems to pick up the 3rd closest neighbor and not the nearest, can anyone help me figure out what I am doing wrong.

Re: How to use attribute rules to get nearest neighbors distance?

JohannesLindner — Fri, 19 Aug 2022 08:11:17 GMT

After line 10, you have to check is dist < minDistance. If yes, update minDistance and name. At the end, return minDistance.

Easier way:

// Attribute Rule // field: empty! var NeighborLayer = FeatureSetByName($datastore, "TestNeighbors", ["NAME"]); var searchDistance = 10000; var NeighborIntersect = Intersects(NeighborLayer, Buffer($feature, searchDistance, "feet")); // return early if nothing nearby, this saves you from all the indentation if(First(NeighborIntersect) == null) { return } // create an array of dictionaries var neighbor_attributes = [] for(var neighbor in NeighborIntersect) { var dist = Distance(neighbor, $feature, "feet") var att = {"NearestNeighbor": neighbor.Name, "Distance": dist} Push(neighbor_attributes, att) } // sort the array by distance function sort_by_distance(a, b) { return a["Distance"] - b["Distance"] } neighbor_attributes = Sort(neighbor_attributes, sort_by_distance) // return the nearest neighbor's name and distance in one go return { "result": {"attributes": neighbor_attributes[0]} }

Re: How to use attribute rules to get nearest neighbors distance?

phess_luckstone — Fri, 19 Aug 2022 10:35:06 GMT

This is awesome and it works on the database side when I bring in those layers directly into Pro from our SDE. However when I tried to use that with a published service it didn't work, any ideas why, is it because it updates both fields at once? When I tried to publish with this attribute rule turned on it wouldn't even let me publish but after deleting the attribute rule it let me.

Re: How to use attribute rules to get nearest neighbors distance?

JohannesLindner — Fri, 19 Aug 2022 10:54:24 GMT

You probably have to publish the TestNeighbors in the same service, too.

If this doesn't work, then I don't know, the whole service thing is very trial-and-error for me.

You could try doing both fields in their own rule. Just select the field and change the return to

return neighbor_attributes[0]["NearestNeighbor"] and

return neighbor_attributes[0]["Distance"]

respectively.

Re: How to use attribute rules to get nearest neighbors distance?

phess_luckstone — Thu, 25 Aug 2022 17:25:04 GMT

Thank you for your reply, I believe that services can't handle array's and using what you had mentioned earlier this code works in our service perfectly, thank you for your help!