Update feature geometry?

AlfredBaldenweck

I have a script that is supposed to replace the geometry of a polygon with a new polygon constructed by reading some of its fields (minX, minY, maxX, maxY).

I can do this with traditional arcpy, but I'm running into issues when trying to do it with the arcgis module.

Specifically, I either get no edits to the geometry if I include a spatial reference OR I get a "read-only" error if I include the spatial reference.

The documentation does not have any examples of actually updating geometry the way that you can update attributes.

Does anyone have any pointers? Thanks

# Get inspectbl as arcgis Featureset
inspectFL = arcgis.features.FeatureLayer(inspectbl,
                                         gis=portal)

inspectFS = inspectFL.query(where=where_clause)
spatref = inspectFS.spatial_reference
for insp in inspectFS:
    # Convert arcgis.feature geometry into
    # arcpy Geometry.
    lowleft = [insp.attributes["mapminx"],
                          insp.attributes["mapminy"]]
    upleft = [insp.attributes["mapminx"],
                         insp.attributes["mapmaxy"]]
    upright = [insp.attributes["mapmaxx"],
                          insp.attributes["mapmaxy"]]
    lowright =[insp.attributes["mapmaxx"], insp.attributes["mapminy"]]
    corners = [lowleft, upleft, upright, lowright]

    geo = arcgis.geometry.Polygon(corners, spatial_reference=spatref)
    geo = arcgis.geometry.Geometry({"rings":corners,
                                    "spatial_reference": {"wkid":spatref}})

    insp.set_value(field_name="shape",
                   value= geo)

    inspectFL.edit_features(updates=inspectFS,
                        use_global_ids=True)

AlfredBaldenweck

Ok, so as it turns out, it was not an issue of the final point, although I've added that just in case.

The actual issue was that I was not nesting the coordinates deep enough.

The "rings" needs to be a list of lists of coordinate pairs, like:

[[[x1,y1], [x2,y2]]]

I had it as

[[x1,y1, [x2, y2]]

Final working is

# Get inspectbl as arcgis Featureset
inspectFL = arcgis.features.FeatureLayer(inspectbl,
                                         gis=portal)
inspectFS = inspectFL.query(where=where_clause)
spatref = inspectFS.spatial_reference
for insp in inspectFS:
    # Convert arcgis.feature geometry into
    # arcgis.geometry.Geometry.
    lowleft = [insp.attributes["mapminx"],
                          insp.attributes["mapminy"]]
    upleft = [insp.attributes["mapminx"],
                         insp.attributes["mapmaxy"]]
    upright = [insp.attributes["mapmaxx"],
                          insp.attributes["mapmaxy"]]
    lowright =[insp.attributes["mapmaxx"], insp.attributes["mapminy"]]
    corners = [[lowleft, upleft, upright, lowright, lowleft]]

    geo = arcgis.geometry.Geometry({"rings":corners,
                                    "spatial_reference":
                                        {"wkid":spatref}})

    insp.set_value(field_name="shape",
                   value= geo)
x = inspectFL.edit_features(updates=inspectFS,
                            use_global_ids=True)

Thanks everyone

View solution in original post

DavidSolari

Might be worth using the as_dict instance method and from_dict class method to create a new feature with matching attributes instead of editing the original object. Heavy handed but if it works, it works!

MobiusSnake

I might be mistaken about this, but I don't think your polygons are valid. I'm pretty sure the first point needs to be repeated as the last point to close it out, like this:

corners = [lowleft, upleft, upright, lowright, lowleft]

AlfredBaldenweck

That's an interesting thought and I'll check it out, but it works with only four points in normal arcpy

with arcpy.da.UpdateCursor(inspectbl,
                           ['SHAPE@', "mapminx", "mapminy",
                            "mapmaxx", "mapmaxy", "OID@"],
                           where_clause= where_clause) as cursor:
    for row in cursor:
        lowleft = arcpy.Point(row[1], row[2])
        upleft = arcpy.Point(row[1], row[4])
        upright = arcpy.Point(row[3], row[4])
        lowright = arcpy.Point(row[3], row[2])
        corners = arcpy.Array([lowleft, upleft, upright, lowright])
        row[0] = arcpy.Geometry("polygon", corners)
        cursor.updateRow(row)

so I'm not certain that's it

AlfredBaldenweck