topic How does ArcGIS Pro calculate INSIDE point for Feature to Point in Polygon? in ArcGIS Pro Questions

How does ArcGIS Pro calculate INSIDE point for Feature to Point in Polygon?

Polymegane — Thu, 15 Feb 2024 08:13:28 GMT

I have used Arc GIS PRO 3.1.2

I seek clarification on how ArcGIS Pro calculates the inside point for Feature to Point in Polygon.

According to the Esri guide page, the summary indicates that it uses "the center of gravity (centroid) of the polygon" . And "If the point_location parameter is set to INSIDE, Polygon features—The output point will be inside the polygon."

https://pro.arcgis.com/en/pro-app/3.1/tool-reference/data-management/feature-to-point.htm

However, the guide does not specify how the inside point is determined from the centroid point.

If anyone is familiar with this algorithm or specifications, please provide insight.

Re: How does ArcGIS Pro calculate INSIDE point for Feature to Point in Polygon?

Eugene_Adkins — Thu, 15 Feb 2024 10:06:00 GMT

I am not a developer but I believe the process is based on the mathematical center of either length or X/Y location. To see the centroid of a collection of features you can highlight/select them in your aprx, then on the edit ribbon you can select the move tool. I believe this will give a visual of the centroid without running the analysis tool. The select and move process will also reveal the centroid for single features.

The centroid for a point is the actual center regardless of symbology size. The centroid for a line is the mathematical center (50 feet/meters would have the centroid located at 25 feet/meters). The centroid for a polygon is the center of the area’s measurement.

This may not be the exact answer you are looking for but I hope it helps. Remember, by selecting the feature and activating the move tool on the project ribbon’s edit tab, you can visualize the feature(s) centroid. Perhaps that part alone will help.

Re: How does ArcGIS Pro calculate INSIDE point for Feature to Point in Polygon?

DanPatterson — Thu, 15 Feb 2024 11:42:39 GMT

How To: Calculate Feature Centroids (esri.com)

The algorithms for the specific calculation are proprietary, but there are two basic concepts used.

But you will have to read the link and see if you can come up with some ideas based on the following example.

some options:

pole of inaccessibility for polygons (numerous references)

polylabel: A fast algorithm for finding the pole of inaccessibility