topic Re: Help using PointGeometry with SelectLayerByLocation in Python Questions

Help using PointGeometry with SelectLayerByLocation

ZoltanSzecsei — Sat, 11 Dec 2021 21:38:45 GMT

Hi,

The following code fails:

pg = arcpy.PointGeometry(vert,'None',True)
arcpy.SelectLayerByLocation_management("hgt_feats", "WITHIN_A_DISTANCE_3D", pg, 0.005, 'NEW_SELECTION')

with:

File "Z:/Projects/Development/python/ToGround/ToGround.py", line 140, in <module>
arcpy.SelectLayerByLocation_management("hgt_feats", "WITHIN_A_DISTANCE_3D", pg, 0.005, 'NEW_SELECTION')
File "C:\Program Files (x86)\ArcGIS\Desktop10.6\ArcPy\arcpy\management.py", line 7873, in SelectLayerByLocation
raise e
RuntimeError: Object: Error in executing tool

I'm trying to see if there is an underlying polygon vertex at a specific XYZ location.

I do not need to select the underlying polygon, I just need to know if there is one at that location

Any help would be appreciated.

Regards and thanks,

Zoltan

Re: Help using PointGeometry with SelectLayerByLocation

DanPatterson_Retired — Fri, 11 Jan 2019 19:47:35 GMT

PointGeometry—ArcPy classes | ArcGIS Desktop intersects perhaps, if you want to work with arcpy geometry objects

The Select Layer By Location—Data Management toolbox | ArcGIS Desktop are using feature layers

Re: Help using PointGeometry with SelectLayerByLocation

ZoltanSzecsei — Fri, 11 Jan 2019 19:59:02 GMT

Hi Dan

I'll take a deeper look at the Point Geometry classes - but I did find plenty of examples using Geometry with SelectLayerByLocation, so I was wondering why my forehead has square indentations and my keyboard broken 🙂

Thanks and keep well,

Zoltan

Re: Help using PointGeometry with SelectLayerByLocation

DarrenWiens2 — Fri, 11 Jan 2019 20:09:02 GMT

Try specifying a spatial reference on your PointGeometry, even if it is unprojected.

Re: Help using PointGeometry with SelectLayerByLocation

ZoltanSzecsei — Fri, 11 Jan 2019 20:15:01 GMT

I have - and have also set arcpy.env.outputCoordinateSystem = arcpy.SpatialReference(blah blah)

It is a projected system with metric coords

Dan's put me on to using geometry methods - now that I take a deeper look, it is a better way to solve my particular issue - I'm just busy wrapping my head around using disjoint/intersect/whatever...........

Re: Help using PointGeometry with SelectLayerByLocation

ZoltanSzecsei — Fri, 11 Jan 2019 20:23:50 GMT

AAaargh! Yes! (Darren says: Try specifying a spatial reference on your PointGeometry)

I override it with 'None', so that negates my env setttings.

I've now added the Spatial Reference into the arcpy.PointGeometry() and it is now working.

Big thanks Darren 🙂

Zoltan

Re: Help using PointGeometry with SelectLayerByLocation

JoshuaBixby — Fri, 11 Jan 2019 20:37:12 GMT

You didn't override it with None, you just created a point geometry without one. In your original code, I assume vert is an ArcPy Point, and ArcPy Points don't have spatial references so there is nothing to override.

Re: Help using PointGeometry with SelectLayerByLocation

DanPatterson_Retired — Fri, 11 Jan 2019 21:24:17 GMT

Select by Location according to the help files, requires 2 feature layers as input. (A hidden feature of arcpy? )

Zoltan, do you have the example where an arcpy geometry object and a feature layer made it work?

Re: Help using PointGeometry with SelectLayerByLocation

JoshuaBixby — Sat, 11 Dec 2021 21:38:48 GMT

With ArcGIS Pro, not sure whether from 1.0 or a later release, you can use Select Layer By Location with only ArcPy geometries. The Select Layer By Location—Data Management toolbox | ArcGIS Pro alludes to it rather than stating it directly:

Usage
If the input is a feature class or dataset path, this tool will automatically create and return a new layer with the result of the tool applied.

>>> import arcpy
>>> 
>>> SR = arcpy.SpatialReference(3857)
>>> polys = [
...     arcpy.FromWKT('POLYGON((0 0, 10 0, 10 10, 0 10, 0 0))', SR),
...     arcpy.FromWKT('POLYGON((11 11, 21 11, 21 21, 11 21, 11 11))', SR),
...     arcpy.FromWKT('POLYGON((0 11, 5 11, 5 16, 0 16, 0 11))', SR)
... ]
>>> pt = arcpy.FromWKT('POINT(10.5 10.5)', arcpy.SpatialReference(3857))
>>> 
>>> fl, = arcpy.SelectLayerByLocation_management(
...     polys,
...     'WITHIN_A_DISTANCE',
...     pt,
...     1.0,
...     'NEW_SELECTION'
... )
>>> fl.getSelectionSet()
{1, 2}
>>> 
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

The IDs returned from getSelectionSet() are offset by 1 from the index of the list passed to it.

In terms of ArcGIS Desktop/ArcMap, this new functionality was not supposed to be back ported, but it appears to have been back ported because I can run this code with 10.6.1. That said, I think using an ArcPy geometry as the select_features has worked for several versions.

Re: Help using PointGeometry with SelectLayerByLocation

DanPatterson_Retired — Fri, 11 Jan 2019 22:09:28 GMT

That makes sense (like the interactive featurelayer creation in tools for Pro

... but it does the arcpy's PointGeometry Zoltan is using work?

Re: Help using PointGeometry with SelectLayerByLocation

JoshuaBixby — Fri, 11 Jan 2019 22:45:48 GMT

Should it work for Zoltan with the PointGeometry, I think so, and it appears to be running without errors.

I can't say I am a fan of the changes to Select Layer by Attributes and Selection Layer By Location. The tools are called "Select Layer," I don't see what is wrong with requiring an actual layer for the in_layer parameter, which is the historical behavior. The newfangled, "convenient" behavior both confuses the semantics of the tools as well as changes some of the behaviors of the tools when using ArcPy geometries as the select_features. I find it humorous and annoying how "backwards compatibility" is so often used as the excuse when my organization asks about changing ArcPy behavior, but it doesn't seem to stop Esri from changing long-standing tool behavior when they want.

Re: Help using PointGeometry with SelectLayerByLocation

DanPatterson_Retired — Fri, 11 Jan 2019 22:59:20 GMT

on 2.3 beta, and I couldn't even get your code to work until I removed the comma on line 9 an

it didn't like fl.getSelectionSet(), and I had to use

for i in fl:
print(i)

f1635DCC2_72BF_41B1_8863_C2A2
f1635DCC2_72BF_41B1_8863_C2A2
2

So 2.3 will have more changes if you weren't using Pro 2.3, beta-2

Re: Help using PointGeometry with SelectLayerByLocation

JoshuaBixby — Sat, 12 Jan 2019 01:52:18 GMT

I last tested with Python 3 for ArcPy 10.6.1 on Linux, an ArcGIS Server-based ArcPy bundle. So, it could be part of what I did only works on either 10.6.1, Linux, or both!

Regarding Pro, I will have to test again next week once I get access again to a machine with it installed. What I have found with Pro is that certain ArcPy code works/behaves differently when run from within the application vs. outside of the application. I have logged several bugs recently where code that should work in a script being executed with the bundled Python interpreter doesn't work, but the same code does work within the Pro application either from a script tool or interactive Python window.

Re: Help using PointGeometry with SelectLayerByLocation

DanPatterson_Retired — Sat, 12 Jan 2019 02:06:58 GMT

To be expected since the 'arcpy's (in it's various incarnations ) are indeed different.

Python 3.6.6 for current ArcGIS Pro. I don't think that will change much if at all.

3.6.8 ended the 3.6* line, 3.7* is up to 3.7.2 (stable) and 3.8* is under development.

Re: Help using PointGeometry with SelectLayerByLocation

ZoltanSzecsei — Sat, 12 Jan 2019 05:41:04 GMT

Yes it does

Re: Help using PointGeometry with SelectLayerByLocation

ZoltanSzecsei — Sat, 12 Jan 2019 05:50:07 GMT

Actually (psychologically) I did "override" it.

If one sets and env to a SRS/CRS, one should be able to assume that all dimension and coordinate related values would be interpreted by ArcGIS to be in the CRS set by the env.

By placing 'None' in a specific command, that (intuitively) explicitly says "override the env requested CRS"

I know this is about symantecs of speach, but I make this point because when ESRI provide certain settings, certain expectations are also "enabled".

HTH

Re: Help using PointGeometry with SelectLayerByLocation

ZoltanSzecsei — Sat, 12 Jan 2019 05:53:34 GMT

No - this was my first attempt - but see my post with screenshot, above - it does work.

Re: Help using PointGeometry with SelectLayerByLocation

JoshuaBixby — Sat, 12 Jan 2019 14:20:41 GMT

I know what you are saying, and agree, about expectations. About 1/3 of the defects I log are where the software works but the behavior doesn't agree with documentation. I don't care which one Esri fixes, either the software or the documentation, but even getting documentation updated has taken multiple versions. I get fixing software defects takes time, but the slowness up addressing documentation issues has always frustrated me greatly.

Re: Help using PointGeometry with SelectLayerByLocation

ZoltanSzecsei — Sat, 12 Jan 2019 14:37:53 GMT

OK - it seems not to work reliably, si I need to rethink my approach.

I'll start a new thread called "Efficient way to check if a vertex coincides with another feature's vertex"

Re: Help using PointGeometry with SelectLayerByLocation

JoshuaBixby — Sat, 12 Jan 2019 14:42:47 GMT

In your new thread, explain what isn't working reliably, the geoprocessing tools themselves or the spatial analysis part.