topic Re: Seeking a tool like 'zonal statistics as table' but for a polygons inside another polygon in ArcGIS Pro Questions

Seeking a tool like 'zonal statistics as table' but for a polygons inside another polygon

HopeHauptman — Sat, 04 Sep 2021 00:31:57 GMT

Is there a tool for finding the majority type by area for a polygon bounded by another polygon layer. Like a 'zonal statistics as table' tool can do for a raster bounded by a polygon? I have tried:

Summarize within (no majority)
Dissolve (no majority)
Dissolve boundary (no majority)

Re: Seeking a tool like 'zonal statistics as table' but for a polygons inside another polygon

DanPatterson — Sat, 04 Sep 2021 00:51:56 GMT

From

Zonal Statistics as Table (Spatial Analyst)—ArcGIS Pro | Documentation

When the value input is integer, all of the statistics (Mean, Majority, Maximum, Median, Minimum, Minority, Percentile, Range, Standard deviation, Sum, and Variety) are available for calculation.

If you have a floating point raster then majority and a few others aren't available... you could scale and "int" the raster in that case to get integers if you don't mind the data reduction.

One other option might be

Tabulate Area (Spatial Analyst)—ArcGIS Pro | Documentation

but it would be raster and raster and would only give your areas

On a side note, your ovals suggest you are using a Web Mercator coordinate system for your map (and perhaps your data). If that is the case, it is not recommended that you use it for anything that might entail distance, area, etc calculations. Switch to an equal area projected coordinate system or a compromise coordinate system (like UTM etc)

Re: Seeking a tool like 'zonal statistics as table' but for a polygons inside another polygon

HopeHauptman — Sat, 04 Sep 2021 01:50:16 GMT

Thank you so much for your reply! I will try to make the tabulate area work. On your side note: yes it is projected Web Mercator - good eye! I tried to match to the other layers' projection (Albers) using the 'project tool' but it looks the same?

Re: Seeking a tool like 'zonal statistics as table' but for a polygons inside another polygon

DanPatterson — Sat, 04 Sep 2021 01:54:07 GMT

Set the 'map' to the Albers projection.

Or better still, open a new map without any basemap or other data. Add a projected featureclass that you want to use (UTM, albers etc). The first layer sets the coordinate system of the map. Then check the map properties to ensure it is so

Re: Seeking a tool like 'zonal statistics as table' but for a polygons inside another polygon

HopeHauptman — Sat, 04 Sep 2021 02:45:22 GMT

ok I will try that but it is sort of what I did here. I started a new map with no basemap and added the first layer (Albers). The second layer came in with Web Mercator and did not adapt to the first layer...

By set the map to Albers (your first suggestion) does that mean use the 'Projections and Transformations tool' or 'define projection tool'? If use define projection and change from Web Merc. to Albers it it puts the area off the coast of Australia

Re: Seeking a tool like 'zonal statistics as table' but for a polygons inside another polygon

DanPatterson — Sat, 04 Sep 2021 02:48:23 GMT

Right-click on the map's name in the table of contents

Select Properties from the popup

Select Coordinate System... make sure it is set to what you want. In my example, it was set by the first layer I added to the map.

Projections and Transformations, Project tool is only used when you want a version of a featureclass in a new coordinate system.

Define Projection.... NEVER use it unless you have a data source that has an Unknown coordinate system.

Telling something it is something when it is not something is just plain wrong and confusing 😉

Re: Seeking a tool like 'zonal statistics as table' but for a polygons inside another polygon

HopeHauptman — Sat, 04 Sep 2021 03:10:28 GMT

Got it. I can't thank you enough. I get confused between Coordinate System and Projection. Much thanks.