topic Re: Selecting Features by Location in Python Questions

Selecting Features by Location

LarissaPizzolato — Sun, 12 Dec 2021 16:38:58 GMT

Hello,

I am trying to select features by location from the "tableName_vctor" layer as defined (and highlighted in red), then export them to a new shapefile and am receiving the following errors (refer to the blue section):

ERROR 000622: Failed to execute (Select Layer By Location). Parameters are not valid.
ERROR 000628: Cannot set input into parameter search_distance.

any insight as to how to fix these errors is much appreciated

thank-you in advance!

try:
    # Iterates through each of the input text files
    for v in list(table):
        # Removes the file extension
        tableName = os.path.splitext(v)[0]
        # Variables
        tableName_line = tableName + str("_line.shp")
        tableName_vctor = tableName + str("_vctor.shp")
        tableName_e = tableName + str ("_e.shp")
        gate = r"C:\gis\gate.shp"
        tableName_sim = tableName + str("_sim.shp")

        # Creating vectors from xy coordinates
        gp.Toolbox = r"C:\Program Files\ArcGIS\ArcToolbox\Toolboxes\Military Analyst Tools.tbx"
        gp.TableToLine_ma(v, tableName_line, "Decimal Degrees", "sLat", "sLon", "eLat", "eLon", "False", "False")
        gp.Project_management(tableName_line, tableName_vctor, "PROJCS['LCC']")

        #Selecting vectors that intersect a line, then points that intersect the vector, then removing the initial selection
        gp.SelectLayerByLocation(tableName_vctor, "intersect", gate, "NEW_SELECTION")
        gp.SelectLayerByLocation(tableName_e, "intersect", tableName_vctor, "ADD_TO_SELECTION")
        gp.SelectLayerByLocation(tableName_vctor, "intersect", gate, "REMOVE_FROM_SELECTION")

        # Write the selected features to a new feature class in the folder
        gp.CopyFeatures(tableName_sim, r"C:\gis\temp")
        
except:
    #If an error occurred while running the script, then print the messages
    print gp.GetMessages()

Re: Selecting Features by Location

MathewCoyle — Mon, 11 Jun 2012 18:54:32 GMT

You can only do selections on layers, not feature classes.

Also, this is the syntax.
SelectLayerByLocation_management (in_layer, {overlap_type}, {select_features}, {search_distance}, {selection_type})

Re: Selecting Features by Location

LarissaPizzolato — Sun, 12 Dec 2021 16:39:00 GMT

When creating the feature layer using the following code,


# Make a layer from the shapefiles
gp.MakeFeatureLayer("tableName_e.shp", "tableName_e_lyr")
gp.MakeFeatureLayer("tableName_vctor.shp", "tableName_vctor_lyr")

I am trying to call on shapefiles that were made earlier in the code (the files in blue), yet I am getting this error:
Failed to execute. Parameters are not valid.
ERROR 000732: Input Features: Dataset tableName_e.shp does not exist or is not supported
Failed to execute (MakeFeatureLayer).

Re: Selecting Features by Location

MarcinGasior — Tue, 12 Jun 2012 12:06:08 GMT

The shapefile you specified is not found in geoprocessing workspace or gp.workspace was not declared.

So you have to:
- declare gp.workspace which contains your shapefiles
or
- provide full path (or variable with path) in gp.MakeFeatureLayer_management() tool

Re: Selecting Features by Location

LarissaPizzolato — Sun, 12 Dec 2021 00:52:15 GMT

# Make a layer from the feature class
        gp.MakeFeatureLayer_management(gate, "gate_lyr")
        gp.MakeFeatureLayer_management(tableName_e, "tableName_e_lyr")
        gp.MakeFeatureLayer_management(tableName_vec, "tableName_vec_lyr")
        print "Feature Layers created."

        #Selecting the vectors that intersect the gate
        gp.SelectLayerByLocation_management(tableName_vec_lyr, "intersect", gate_lyr)
        # Add to selection, points that intersect with the previously selected vectors
        gp.SelectLayerByLocation_management(tableName_e_lyr, "intersect", tableName_vec_lyr, "ADD_TO_SELECTION")
        # Remove initial vector selection
        gp.SelectLayerByLocation_management(tableName_vec_lyr, "intersect", gate_lyr, "REMOVE_FROM_SELECTION")
        # Write the selected features to a new feature class
        gp.CopyFeatures(tableName_e_lyr, tableName_sim)

The feature layers are successfully created, and the first "select layer by location " works, but it doesn't seem to perform the 2 subsequent "select layer by location"'s.

Re: Selecting Features by Location

LarissaPizzolato — Tue, 12 Jun 2012 14:13:42 GMT

It says that the search distance is optional so I have tried to set it as "None", "Null", "No_Value", "", " ", "0", as I do not want to create a buffer, but rather only select the points that intersect with the specified vector... I can't seem to find any other alternative placeholder to setting it as blank.

You need to use the proper syntax.
SelectLayerByLocation_management (in_layer, overlap_type, select_features, search_distance, selection_type)
http://webhelp.esri.com/arcgisdesktop/9.3/body.cfm?id=1877&pid=1865&topicname=Select%20Layer%20By%20Location%20%28Data%20Management%29&tocVisable=0

You are trying to insert "ADD_TO_SELECITON" in the search distance parameter.

Re: Selecting Features by Location

MathewCoyle — Sun, 12 Dec 2021 00:52:20 GMT

Either of these should work.
"" or "#"

gp.SelectLayerByLocation_management(tableName_e_lyr, "intersect", tableName_vec_lyr, "", "ADD_TO_SELECTION")

gp.SelectLayerByLocation_management(tableName_vec_lyr, "intersect", gate_lyr, "#","REMOVE_FROM_SELECTION")

Are you getting an error or anything when these execute? Or just unexpected behaviour?

Re: Selecting Features by Location

NobbirAhmed — Sun, 12 Dec 2021 00:52:23 GMT

After you set an empty string (red) for the search_distance parameter:

gp.SelectLayerByLocation_management(tableName_e_lyr, "intersect", tableName_vec_lyr, "", "ADD_TO_SELECTION")

Please enclose the call with try-except block as follows:

try:
    gp.SelectLayerByLocation_management(tableName_e_lyr, "intersect", tableName_vec_lyr, "", "ADD_TO_SELECTION")

except:
    print gp.GetMessages(2)

What error message do you get now?

Re: Selecting Features by Location

LarissaPizzolato — Sun, 12 Dec 2021 00:52:25 GMT

I added the try and except statement around the select layers by location by did not get any error messages generated.

This is what printed in the python shell:
Feature Layers created. (suggesting that the feature layers were created)
Selecting vectors that intersect the gate for:20041115011426_20041122011013 (this is the start of the select by location commands)
(i'm not sure why this is occuring after the feature layers should have aExecuting: MakeFeatureLayer E:\temp\5464648_vec.shp vec_lyr # # "CP CP VISIBLE NONE;startX startX VISIBLE NONE;startY startY VISIBLE NONE;dispX dispX VISIBLE NONE;dispY dispY VISIBLE NONE;sLat sLat VISIBLE NONE;sLon sLon VISIBLE NONE;theta theta VISIBLE NONE;pCorr pCorr VISIBLE NONE;pkStr pkStr VISIBLE NONE;cCorr cCorr VISIBLE NONE;conf conf VISIBLE NONE;velX velX VISIBLE NONE;velY velY VISIBLE NONE;endX endX VISIBLE NONE;endY endY VISIBLE NONE;eLat eLat VISIBLE NONE;eLon eLon VISIBLE NONE"
Start Time: Tue Jun 12 12:57:06 2012
Executed (MakeFeatureLayer) successfully.
End Time: Tue Jun 12 12:57:06 2012 (Elapsed Time: 0.00 seconds)

I know that the select by location should work because when I do it manually in ArcMap, i'm able to select several features through following the similar set of commands but the automation for this step doesn't seem to run.

        # Variables...
        tableName_e = tableName + str("_e.shp")
        tableName_vec = tableName + str("_vec.shp")
        tableName_e = tableName + str ("_e.shp")
        tableName_sim = tableName + str("_sim.shp")
        gate = r"E:\test\gate.shp"
        end_lyr = tableName + str("_e.lyr")
        vec_lyr = tableName + str("_vec.lyr")
        
 # Make a layer from the feature class
        gp.MakeFeatureLayer_management(gate, "gate_lyr")
        gp.MakeFeatureLayer_management(tableName_e, "end_lyr")
        gp.MakeFeatureLayer_management(tableName_vec, "vec_lyr")
        print "Feature Layers created."

        #Selecting the vectors that intersect the gate
        print "Selecting vectors that intersect the gate for:" + str(tableName)
        
        # Process: Select Layer By Location...
        gp.SelectLayerByLocation_management(vec_lyr, "INTERSECT", gate_lyr, "", "NEW_SELECTION")

        # Process: Select Layer By Location (2)...
        gp.SelectLayerByLocation_management(end_lyr, "INTERSECT", vec_lyr, "", "ADD_TO_SELECTION")

        # Process: Select Layer By Location (3)...
        gp.SelectLayerByLocation_management(vec_lyr, "INTERSECT", gate_lyr, "", "REMOVE_FROM_SELECTION")

        # Write the selected features to a new feature class
        gp.CopyFeatures_management(end_lyr, tableName_sim,  "", "0", "0", "0")

Re: Selecting Features by Location

NobbirAhmed — Sun, 12 Dec 2021 00:52:28 GMT

Which version of ArcGIS you are on?

Please add another print statement in the try block and see whether you get any success message.

try:
    gp.SelectLayerByLocation_management(tableName_e_lyr, "intersect", tableName_vec_lyr, "", "ADD_TO_SELECTION")
    print gp.GetMessages()
except:
    print gp.GetMessages(2)

Re: Selecting Features by Location

LarissaPizzolato — Tue, 12 Jun 2012 17:23:53 GMT

Hello NobbirAhmed,

I am using ArcGIS 9.3.

when I added the additional print message, and the try/except block this error occured:

Executing: SelectLayerByLocation 11013_e.lyr INTERSECT 11013_vec.lyr # ADD_TO_SELECTION 11013_e.lyr
Start Time: Tue Jun 12 14:18:24 2012
Failed to execute. Parameters are not valid.
ERROR 000732: Input Feature Layer: Dataset 20041115011426_20041122011013_e.lyr does not exist or is not supported
ERROR 000732: Selecting Features: Dataset 20041115011426_20041122011013_vec.lyr does not exist or is not supported
Failed to execute (SelectLayerByLocation).

Re: Selecting Features by Location

MathewCoyle — Tue, 12 Jun 2012 17:33:25 GMT

You are referencing layer files that were never created it looks like. MakeFeatureLayer creates a temporary layer in memory, not a layer file.

Re: Selecting Features by Location

LarissaPizzolato — Wed, 13 Jun 2012 12:02:15 GMT

Thanks Mathew!

Re: Selecting Features by Location

MathewCoyle — Sun, 12 Dec 2021 00:52:17 GMT

# Make a layer from the feature class
        gp.MakeFeatureLayer_management(gate, "gate_lyr")
        gp.MakeFeatureLayer_management(tableName_e, "tableName_e_lyr")
        gp.MakeFeatureLayer_management(tableName_vec, "tableName_vec_lyr")
        print "Feature Layers created."

        #Selecting the vectors that intersect the gate
        gp.SelectLayerByLocation_management(tableName_vec_lyr, "intersect", gate_lyr)
        # Add to selection, points that intersect with the previously selected vectors
        gp.SelectLayerByLocation_management(tableName_e_lyr, "intersect", tableName_vec_lyr, "ADD_TO_SELECTION")
        # Remove initial vector selection
        gp.SelectLayerByLocation_management(tableName_vec_lyr, "intersect", gate_lyr, "REMOVE_FROM_SELECTION")
        # Write the selected features to a new feature class
        gp.CopyFeatures(tableName_e_lyr, tableName_sim)

The feature layers are successfully created, and the first "select layer by location " works, but it doesn't seem to perform the 2 subsequent "select layer by location"'s.

You need to use the proper syntax.
SelectLayerByLocation_management (in_layer, overlap_type, select_features, search_distance, selection_type)
http://webhelp.esri.com/arcgisdesktop/9.3/body.cfm?id=1877&pid=1865&topicname=Select%20Layer%20By%20Location%20%28Data%20Management%29&tocVisable=0

You are trying to insert "ADD_TO_SELECITON" in the search distance parameter.