topic Re: addin tool not selecting by location in Python Questions

addin tool not selecting by location

KevinBell1 — Fri, 13 Apr 2018 15:09:18 GMT

I'm making a python addin select tool that allows the user to draw a rectangle and then select points within it to then do stuff. For testing I'm only counting how many points are selected and writing to a log file, but it always returns 0... What am I doing wrong here?

def onRectangle(self, rectangle_geometry):
ext = rectangle_geometry

   array = arcpy.Array()
   array.add(arcpy.Point(ext.XMin, ext.YMin))
   array.add(arcpy.Point(ext.XMin, ext.YMax))
   array.add(arcpy.Point(ext.XMax, ext.YMax))
   array.add(arcpy.Point(ext.XMax, ext.YMin))
   array.add(arcpy.Point(ext.XMin, ext.YMin))
   polygon = arcpy.Polygon(array)
   arcpy.CopyFeatures_management(polygon, "in_memory//Polygon_Extent")
   arcpy.MakeFeatureLayer_management("in_memory//Polygon_Extent", 'selectLyr')

   arcpy.MakeFeatureLayer_management('events', 'eventsLyr')

   arcpy.SelectLayerByLocation_management('eventsLyr', 'INTERSECT','selectLyr')
   n = arcpy.GetCount_management('eventsLyr')

   f = open(r'E:\ArcMap\BuildingServices\20180411_misassignedInspectors\addin\log.txt','a')
   f.write(str(n) + '\n')
   f.close()

   arcpy.Delete_management("in_memory//Polygon_Extent")
   arcpy.Delete_management('selectLyr')
   arcpy.Delete_management('eventsLyr')

Re: addin tool not selecting by location

DanPatterson_Retired — Fri, 13 Apr 2018 16:17:41 GMT

Is everything in the same coordinate system? since getcount honors the extent environment parameter, so it may not be selecting anything because of that.

You would also be wise to add the extent parameters and anything else useful to your output text file

Re: addin tool not selecting by location

KevinBell1 — Fri, 13 Apr 2018 16:34:22 GMT

This isn't even working:

def onRectangle(self, rectangle_geometry):

ext = rectangle_geometry

      f = open('log.txt','a')
      f.write(ext.XMin, ext.XMax, ext.YMin, ext.YMax)
      f.close()

Re: addin tool not selecting by location

JoeBorgione — Sat, 11 Dec 2021 15:29:45 GMT

Kevin- not sure if this'll help, but here's a snippet I use to create a single polygon based on data frame extent:

mxd = arcpy.mapping.MapDocument("CURRENT")
df = arcpy.mapping.ListDataFrames(mxd)[0]
frameExtent = df.extent
XMAX = frameExtent.XMax
XMIN = frameExtent.XMin
YMAX = frameExtent.YMax
YMIN = frameExtent.YMin
#
pnt1 = arcpy.Point(XMIN, YMIN)
pnt2 = arcpy.Point(XMIN, YMAX)
pnt3 = arcpy.Point(XMAX, YMAX)
pnt4 = arcpy.Point(XMAX, YMIN)
#
array = arcpy.Array()
array.add(pnt1)
array.add(pnt2)
array.add(pnt3)
array.add(pnt4)
array.add(pnt1)
Mypolygon = arcpy.Polygon(array)
arcpy.CopyFeatures_management(Mypolygon,"in_memory\\ExtentPoly")
in_poly_layer = arcpy.mapping.ListLayers(mxd,"ExtentPoly",df)[0]‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: addin tool not selecting by location

KevinBell1 — Fri, 13 Apr 2018 21:19:09 GMT

Ya, that code from JSchiener (sp?) was what I started with before violating the zen of python by nesting it rather than keeping it flat!

Re: addin tool not selecting by location

RandyBurton — Sat, 11 Dec 2021 15:29:48 GMT

As a test, do you get a count if you check just before the SelectByLocation?

arcpy.MakeFeatureLayer_management('events', 'eventsLyr')

# check here to see if layer has a count
n = arcpy.GetCount_management('eventsLyr')
print n

arcpy.SelectLayerByLocation_management('eventsLyr', 'INTERSECT','selectLyr')‍‍‍‍‍‍‍

Re: addin tool not selecting by location

KevinBell1 — Mon, 16 Apr 2018 16:24:23 GMT

Yes! I do get a count if I forego the selection. If I do the select by location the count is zero, with out it 258 which is correct.

Re: addin tool not selecting by location

KevinBell1 — Mon, 16 Apr 2018 16:35:37 GMT

How can I ensure the coordinate systems are the same. That's got to be it, but I'm stuck.

The map where the tool is used is in state plane, and the event layer is projecting on the fly from wgs 84. When I'm creating the feature layer for the events there's no option to specify a different coordinate system.

Re: addin tool not selecting by location

DanPatterson_Retired — Mon, 16 Apr 2018 16:41:35 GMT

Keven... Projecting on the fly does nothing but make things look nice on screen and give you a false sense that things are as they should be.

Make the event layer a featureclass, then Project it to the appropriate projection ... or ... unproject the thing that you are trying to use in the selection process so it matches the decimal degree data. Once everything is in the same coordinate system (either projected or geographic) proceed with spatial selections.

Re: addin tool not selecting by location

KevinBell1 — Mon, 16 Apr 2018 17:14:23 GMT

Coordinate systems is GCS_WGS_1984 in the map, and I added

sr = arcpy.SpatialReference(4326)
polygon = arcpy.Polygon(array, sr)

And now I see in the properties that the coord sys are identical but I still get no entry in my log. I do log data from this addin's combo box selection change, but not this. Here's what I'm running.

def onRectangle(self, rectangle_geometry):

ext = rectangle_geometry

   array = arcpy.Array()
   array.add(arcpy.Point(ext.XMin, ext.YMin))
   array.add(arcpy.Point(ext.XMin, ext.YMax))
   array.add(arcpy.Point(ext.XMax, ext.YMax))
   array.add(arcpy.Point(ext.XMax, ext.YMin))
   array.add(arcpy.Point(ext.XMin, ext.YMin))
   sr = arcpy.SpatialReference(4326)
   polygon = arcpy.Polygon(array, sr)
   arcpy.CopyFeatures_management(polygon, "in_memory//Polygon_Extent")
   arcpy.MakeFeatureLayer_management("in_memory//Polygon_Extent", 'selectLyr')
   arcpy.MakeFeatureLayer_management('events', 'eventsLyr')

   f = open(r'E:\ArcMap\BuildingServices\20180411_misassignedInspectors\addin\log.txt','a')
   f.write('what the hell?')
   f.close()

   arcpy.Delete_management("in_memory//Polygon_Extent")
   arcpy.Delete_management('selectLyr')
   arcpy.Delete_management('eventsLyr')

Nothing is written to the log, but the polygon is created in the map, so the def is running. : (

Re: addin tool not selecting by location

DanPatterson_Retired — Mon, 16 Apr 2018 17:28:21 GMT

Print the coordinates... again, you can define anything what you want, it doesn't make it so.

And you are appending to an existing file in your file.open, is that correct?

Re: addin tool not selecting by location

KevinBell1 — Mon, 16 Apr 2018 17:39:26 GMT

Changed f.write('what the hell?') to f.write(ext.XMin, ext.YMin) and nothing is written to the log file that is open to append.

Re: addin tool not selecting by location

KevinBell1 — Mon, 23 Apr 2018 15:15:16 GMT

ESRI Tech support got me going!

def onRectangle(self, rectangle_geometry):

   arcpy.MakeFeatureLayer_management('events', 'eventsLyr')

   arcpy.SelectLayerByLocation_management('eventsLyr', 'INTERSECT',rectangle_geometry.polygon)
   n = arcpy.GetCount_management('eventsLyr')
   f = open(r'E:\ArcMap\BuildingServices\20180411_misassignedInspectors\addin\log.txt','a')
   f.write(str(n) + '\n')
   f.close()

arcpy.Delete_management('selectLyr')
arcpy.Delete_management('eventsLyr')