topic Import polygons with auto clip? in Data Management Questions

Import polygons with auto clip?

BruceLang — Tue, 02 Feb 2016 20:42:02 GMT

This seems so basic, but I'm not finding a solution.

I have; (1) a polygon shapefile containing multiple polygons, and (2) a versioned enterprise geodatabase (SQL server) polygon layer. The shapefile and geodatabase contain the same file structure.

I would like to import the shapefile polygons into the geodatabase AND remove (clip away) any overlap from the geodatabase layer.

The data layers consist of zoning polygons. The geodatabase layer is the existing county zoning layer, covering the entire county. The shapefile contains new zoning areas to import into the geodatabase layer. The new areas must remove any overlapping area from the geodatabase layer.

I can do this manually in an edit session, but only one polygon at a time. (a) copy area from shapefile, (b) paste into geodatabase layer, and (c) select "clip" (from the editor menu) clipping away overlap from geodatabase. When trying the same process with multiple polygon's, the clip option was not available.

Thanks in advance.

BTW: ArcGIS 10.3.1 Standard

Re: Import polygons with auto clip?

WesMiller — Tue, 02 Feb 2016 20:52:32 GMT

Have you looked at Clip—Help | ArcGIS for Desktop in toolbox?

Re: Import polygons with auto clip?

BruceLang — Tue, 02 Feb 2016 21:05:33 GMT

Thanks Wes,

Yes, but this creates a new feature class. It does not (seem to) work with an existing layer as in my case.

Re: Import polygons with auto clip?

WesMiller — Tue, 02 Feb 2016 21:20:03 GMT

You could truncate and append the new features in the old feature class.

Truncate Table—Help | ArcGIS for Desktop

Append—Help | ArcGIS for Desktop

Edit: You might want to make a copy of your data before hand.

Re: Import polygons with auto clip?

BruceLang — Tue, 02 Feb 2016 21:44:09 GMT

Neither of these are appropriate either. The truncate does not work with versioned data and does not consider the "shape" of an area. Append does not "clip" out the area, but creates new areas from the overlaps.

Here's a visual example of what I'm trying to do:

Re: Import polygons with auto clip?

WesMiller — Tue, 02 Feb 2016 21:54:39 GMT

Use Erase—Help | ArcGIS for Desktop then append the polys(shapefile)

Re: Import polygons with auto clip?

ChrisDonohue__GISP — Tue, 02 Feb 2016 23:52:59 GMT

I run into this also with my work for the City and have not come up with a great way to do this (but am still looking). Here's two workflows that may help:

Given the geoprocessing limitations that come with Versions, I usually opt to dump the data out to a File Geodatabase, do the necessary geoprocessing there, delete the affected polygons in the Version, then Append back in the new polygons to the Version. Tedious, but it works.

Another workflow that can be effective if there are only a few features to update is to use the Attribute Transfer tool (Spatial Adjustment Toolbar) to update the geometry and/or the attributes while still in the Version by "transferring" the information from a source feature class. If you do go this route, 2 tips: make sure both the source and target layers are selectable, and after making the transfer, realize you may have to Refresh the view to see the geometry changes (it often lags, making it seem like nothing happened).

EDIT - added more images.

Chris Donohue, GISP

Re: Import polygons with auto clip?

JayantaPoddar — Wed, 03 Feb 2016 05:37:29 GMT

One can follow these steps (You can optimize the workflow by creating a model).

1. Exporting the shapefile to geodatabase (Let me call it "Feat2")

Feature Class To Feature Class—Help | ArcGIS for Desktop

2. Remove the overlapping area of Feat1 using Feat2 using Erase (Analysis) tool.

Erase—Help | ArcGIS for Desktop

3. Append Feat2 to Feat1.

Append—Help | ArcGIS for Desktop

Re: Import polygons with auto clip?

BruceLang — Thu, 04 Feb 2016 17:39:53 GMT

Chris,

Have not tried the first suggested process because it seems to work with non-overlapping areas. Our entire county is covered by zoning polygons.

The second process I'm very familiar with, however I've not used the "Transfer Geometry" option. This did not work either - or I was doing it wrong. I'll explain by using my example image, in another message: When zones "e" & "f" are transferred to zone "a", the entire shape of "a" is modified to match the shape and size of "e" or "f" instead of "clipping" away their shape from "a"

Re: Import polygons with auto clip?

BruceLang — Thu, 04 Feb 2016 17:47:36 GMT

Jayanta,

I've looked at "erase", but it's only available with an "ArcGIS for Desktop Advanced" license. Plus, erase outputs to a new feature class, that is, it does not erase features from an existing layer.

Re: Import polygons with auto clip?

DarrenWiens2 — Sat, 11 Dec 2021 17:23:12 GMT

Here's a Python script that should emulate your manual editing task using geometry objects, in place, and Basic licensing. Caveats: I have no idea if this works for versioned data. This is a n^2 operation, meaning for each feature in the original dataset, it does something for each feature in the new dataset. This may be problematic for large datasets.

>>> main = 'main' # main dataset
... new = 'new' # new dataset
... with arcpy.da.UpdateCursor(main,'SHAPE@') as uCursor:
...    for uRow in uCursor: # loop through main polygons
...        with arcpy.da.SearchCursor(new,'SHAPE@') as sCursor:
...            for sRow in sCursor: # loop through new polygons
...                uRow[0] = uRow[0].difference(sRow[0]) # remove overlaps between main/new
...                uCursor.updateRow(uRow) # update main polygons minus new polygons
... arcpy.Append_management([new],'main',"NO_TEST") # append new polygons to main

Original (no overlaps):

With new shapefile overlain:

Delete 'differences' (no overlaps, voids for new features):

Append new to main (no overlaps):

Re: Import polygons with auto clip?

ChrisDonohue__GISP — Thu, 04 Feb 2016 19:11:55 GMT

Erase (Analysis) doesn't work in a Versioned environment, unfortunately, due to the constraint on processes that create new data. However, if you export your data to a File Geodatbase, you are free of the enterprise geodatabase limitations. You can then do all the processing of the data, then Append the results back into the Version.

If you don't have the Advanced license required to have Erase available, there are several workarounds:

1. There's Python - see the script Darren Wiens posted.

2. If you have XToolsPro (third-party software add-on), there is an Erase Features function.

3. You can run a Union (Analysis) which is available at all license levels, and then go into the attribute table and do a selection to essentially recreate the results of an Erase.

The output feature class will contain a FID_<name> attribute for each of the input feature classes. For example, if one of the input feature classes is named Soils, there will be a FID_Soils attribute on the output feature class. FID_<name> values will be -1 for any input feature (or any part of an input feature) that does not intersect another input feature. Attribute values for the other feature classes in the union where no intersection is detected will not be transferred to the output feature in this case.

ArcGIS Help 10.1 - Union (Analysis)

Chris Donohue, GISP