topic Large decimal degree values when calculating geometry for latitude and longitude in ArcGIS Pro Questions

Large decimal degree values when calculating geometry for latitude and longitude

BrentDavis — Thu, 24 Sep 2020 18:19:55 GMT

Often we need to edit a polygon feature and recalculate a longitude and latitude field for the centroid of the feature. Historically, we have been doing this editing calculation within arcmap, but have been trying it out in ArcGIS pro.

Unfortunately when we try and calculate the centroid x-coordinate and centroid y-coordinate for longitude and latitude in decimal degrees we are getting very large values as compared to the workflow used in arcmap. It looks like the format is being displayed in meters.

Below are the setting we are using:

Here is the output of (Lat,Lon) for a test feature that was created.

Any ideas on how to reproduce the calculate geometry function from arcmap?

Thanks

Re: Large decimal degree values when calculating geometry for latitude and longitude

DanPatterson — Thu, 24 Sep 2020 18:41:07 GMT

what are you using to calculate the values? It looks like your data are in a projected coordinate system or it has been defined incorrectly as geographic when it is indeed projected

Re: Large decimal degree values when calculating geometry for latitude and longitude

BrentDavis — Thu, 24 Sep 2020 18:47:39 GMT

Dan thanks for your reply.

I am not sure where to find this out. These are the spatial reference properties of the feature layer in question.

Re: Large decimal degree values when calculating geometry for latitude and longitude

DanPatterson — Thu, 24 Sep 2020 19:21:10 GMT

right-click on the layer, select properties, look for spatial reference.

Again, what did you use/do to calculate the values for the coordinates?

Re: Large decimal degree values when calculating geometry for latitude and longitude

BrentDavis — Thu, 24 Sep 2020 19:33:57 GMT

We are right clicking a field in the attribute table for the layer and clicking on 'Calculate Geometry'. I believe this is the same thing as using the 'Calculate Geometry Attributes' geoprocessing tool.

I've screenshot two images: The Calculate Geometry tool and the Spatial Reference information for the layer.

Re: Large decimal degree values when calculating geometry for latitude and longitude

DanPatterson — Thu, 24 Sep 2020 19:39:16 GMT

You do have a projected coordinate system, it seems that the long/lat output request isn't being supported

Use

Add Geometry Attributes (Data Management)—ArcGIS Pro | Documentation

to compare

Re: Large decimal degree values when calculating geometry for latitude and longitude

BrentDavis — Thu, 24 Sep 2020 19:46:44 GMT

Attached is the settings used for Add Geometry Attribute and what attributes were created for a selected feature. Looks like I'm getting the same values.

Re: Large decimal degree values when calculating geometry for latitude and longitude

DanPatterson — Thu, 24 Sep 2020 20:40:32 GMT

So confirmed that the data are in a projected coordinate system.

Now try to get them calculated in a GCS NAD83 (geographic coordinate system) to get them in decimal degrees,

You might have missed the help section....

If a coordinate system is specified, the length and area calculations will be in the units of that coordinate system unless different units are selected in the Length Unit and Area Unit parameters.

Re: Large decimal degree values when calculating geometry for latitude and longitude

BrentDavis — Thu, 24 Sep 2020 21:16:41 GMT

O.k. GCS NAD83 did work for the coordinate system. Thank you.

Is this because I was using a PCS for my coordinate system but decimal degrees should be using a GCS?

Re: Large decimal degree values when calculating geometry for latitude and longitude

DanPatterson — Thu, 24 Sep 2020 22:27:18 GMT

Yes... GCS (geographic coordinate systems) are in decimal degrees.

PCS (projected coordinate systems) are usually in meters, but a few countries opt for feet (international or U.S.)

Datums are a whole different issue... basically describing Earth's shape (simply) so if those fundamentals change, then coordinate values will change for a fixed location on Earth... hence, referred to as "datum shift".

There are tons (or tonnes) of great references out there

Re: Large decimal degree values when calculating geometry for latitude and longitude

ABishop — Thu, 30 Sep 2021 17:40:49 GMT

@DanPatterson

I know this post is from over a year ago, but it is the only one that is similar to what I am dealing with currently in a model that I have built for calculating geometry attributes in an acreage field for our parcel polygons. I have another post out there where a gentleman is trying to assist me, but he isn't clarifying on how or where to effectively round the decimal to 2 in my model script. Could you possibly assist me with this Dan? Any help you can offer will be GREATLY appreciated! See the model script in the python window below.

# -*- coding: utf-8 -*- """ Generated by ArcGIS ModelBuilder on : 2021-09-30 10:58:27 """ import arcpy def GeometryCalc(): # GeometryCalc # To allow overwriting outputs change overwriteOutput option to True. arcpy.env.overwriteOutput = False arcpy.ImportToolbox(r"c:\program files\arcgis\pro\Resources\ArcToolbox\toolboxes\Data Management Tools.tbx") # Model Environment settings with arcpy.EnvManager(scratchWorkspace=r"C:\Users\abishop\AppData\Local\Temp\ArcGISProTemp10544\1ba0f558-c873-4c6c-be6d-dc08393016c0\Default.gdb", workspace=r"C:\Users\abishop\AppData\Local\Temp\ArcGISProTemp10544\1ba0f558-c873-4c6c-be6d-dc08393016c0\Default.gdb"): mcpagis_DBO_Parcels = "K:\\GIS_TOOLS\\DB\\merlin.sde\\mcpagis.DBO.Cadastre__Features\\mcpagis.DBO.Parcels" # Process: Make Feature Layer (Make Feature Layer) (management) DBO_Parcels_Layer = "DBO.Parcels_Layer" with arcpy.EnvManager(scratchWorkspace=r"C:\Users\abishop\AppData\Local\Temp\ArcGISProTemp8392\0686a1b7-5a62-4965-97f7-463b179295c6\Default.gdb", workspace=r"C:\Users\abishop\AppData\Local\Temp\ArcGISProTemp8392\0686a1b7-5a62-4965-97f7-463b179295c6\Default.gdb"): arcpy.management.MakeFeatureLayer(in_features=mcpagis_DBO_Parcels, out_layer=DBO_Parcels_Layer, where_clause="GIS_ACRES = 0 Or GIS_ACRES IS NULL", workspace="", field_info="OBJECTID OBJECTID VISIBLE NONE;PARCEL PARCEL VISIBLE NONE;PREFIX PREFIX VISIBLE NONE;SUFFIX1 SUFFIX1 VISIBLE NONE;SUFFIX2 SUFFIX2 VISIBLE NONE;GIS_ACRES GIS_ACRES VISIBLE NONE;KIND KIND VISIBLE NONE;ANGLE ANGLE VISIBLE NONE;SIZE_ SIZE_ VISIBLE NONE;DATE_CREATED DATE_CREATED VISIBLE NONE;DATE_UPDATED DATE_UPDATED VISIBLE NONE;SHAPE SHAPE VISIBLE NONE;SHAPE.area SHAPE.area VISIBLE NONE;SHAPE.len SHAPE.len VISIBLE NONE") # Process: Calculate Geometry Attributes (Calculate Geometry Attributes) (management) with arcpy.EnvManager(scratchWorkspace=r"C:\Users\abishop\AppData\Local\Temp\ArcGISProTemp8392\0686a1b7-5a62-4965-97f7-463b179295c6\Default.gdb", workspace=r"C:\Users\abishop\AppData\Local\Temp\ArcGISProTemp8392\0686a1b7-5a62-4965-97f7-463b179295c6\Default.gdb"): DBO_Parcels_Layer_2_ = arcpy.management.CalculateGeometryAttributes(in_features=DBO_Parcels_Layer, geometry_property=[["GIS_ACRES", "AREA"]], length_unit="", area_unit="ACRES", coordinate_system="PROJCS[\"NAD_1983_StatePlane_Florida_West_FIPS_0902_Feet\",GEOGCS[\"GCS_North_American_1983\",DATUM[\"D_North_American_1983\",SPHEROID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],PROJECTION[\"Transverse_Mercator\"],PARAMETER[\"False_Easting\",656166.6666666665],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Central_Meridian\",-82.0],PARAMETER[\"Scale_Factor\",0.9999411764705882],PARAMETER[\"Latitude_Of_Origin\",24.33333333333333],UNIT[\"Foot_US\",0.3048006096012192]]", coordinate_format="SAME_AS_INPUT")[0] if __name__ == '__main__': GeometryCalc()

Re: Large decimal degree values when calculating geometry for latitude and longitude

SUSANMYERS — Fri, 28 Apr 2023 17:58:23 GMT

Hi Dan,

When calculating geometry for latitude and longitude fields, ArcGIS Pro 3.03 gives me eight decimals: DDMMSS.ssssssss

I guess someone in the world wants that, but we just want DDD° MM' SSS.sss (like the good old days in ArcGIS Desktop). Choosing WGS84 vs. a state plane coordinate system does not appear to affect this.

We are choosing the following option for coordinate format: (Degrees Minutes Seconds (DDD° MM' SSS.ss" <N|S|E|W>)

While I am asking, perhaps there is a way to add these fields so that they automatically update when points are added to the table?