topic Flow Path Parameters from 2D Line Python Error in Water Resources Questions

Flow Path Parameters from 2D Line Python Error

JeffreyZimmerman__Jr_ — Mon, 09 Feb 2015 16:50:42 GMT

I am trying to run a python script in PythonWin that first creates the longest flow path for subwatersheds then computes the flow path parameters from 2D line. I keep getting a error of "Object reference not set to an instance of an object" for the Flow Path Parameters from 2D line part of the script. Here is my code, wondering if I'm missing something? I'm using ArcMap 10.1 and Feb. 2014 ArcHydro release.

# Import arcpy module
import arcpy
import ArcHydroTools
from arcpy.sa import *
arcpy.CheckOutExtension("Spatial")
arcpy.env.overwriteOutput = True

# Local variables:
ned10m = "L:\\srbcgis\\Projects\\Cumulative_Impacts\\Data\\Availability_Data\\ned10m"
Wshedtest = "C:\\CWUAS\\cwuas_10m.gdb\\CWUAS\\Wshedtest"
WshedtestPt = "C:\\CWUAS\\cwuas_10m.gdb\\CWUAS\\WshedtestPt"
Catchment = "C:\\CWUAS\\cwuas_10m.gdb\\CWUAS\\Catchment"
LFPCatchment = "C:\\CWUAS\\cwuas_10m.gdb\\CWUAS\\LFPCatchment"
fdrlake = "C:\\CWUAS\\Rasters\\CWUAS\\fdrlake"
LongestFlowPath = "C:\\CWUAS\\cwuas_10m.gdb\\CWUAS\\LongestFlowPath"
PTSLP_GP = "C:\\CWUAS\\cwuas_10m.gdb\\CWUAS\\PTSLP_GP"

# Process: Longest Flow Path for Subwatersheds
ArcHydroTools.LongestFlowPathForSubwatersheds(Wshedtest, WshedtestPt, Catchment, LFPCatchment, fdrlake, LongestFlowPath)

# Process: Flow Path Parameters from 2D Line
ArcHydroTools.FlowPathParametersFrom2DLine(LongestFlowPath, ned10m, PTSLP_GP)

Re: Flow Path Parameters from 2D Line Python Error

XanderBakker — Mon, 09 Feb 2015 17:10:53 GMT

This is typically a COM error (might be from your ArcHydro installation). Don't think the error is caused by your python script. Could you show the complete error anyhow?

If you perform this manually, with the same data, does the error still occur?

Re: Flow Path Parameters from 2D Line Python Error

JeffreyZimmerman__Jr_ — Mon, 09 Feb 2015 17:20:24 GMT

I can run the tool in ArcMap with no problems. I also created a ModelBuilder model first and ran it successfully. I then exported it to a python script. When I run it from PythonWin, I get the below error. Seems like ArcMap has something running that the tool needs, but when taken out of the ArcMap world, it errors. I am downloading the 1/22/2015 ArcHydroTools10.1x64 version now.

Here is the complete error:

Traceback (most recent call last):

File "C:\Python27\ArcGIS10.1\Lib\site-packages\Pythonwin\pywin\framework\scriptutils.py", line 326, in RunScript

exec codeObject in __main__.__dict__

File "L:\srbcgis\Projects\Cumulative_Impacts\Data\Availability_Data\MNSLP_GP.py", line 35, in <module>

ArcHydroTools.FlowPathParametersFrom2DLine(LongestFlowPath, ned10m, PTSLP_GP)

File "C:\Program Files (x86)\ESRI\WaterUtils\ArcHydro\bin\ArcHydroTools.py", line 6668, in FlowPathParametersFrom2DLine

raise e

ExecuteError: Object reference not set to an instance of an object.

Failed to execute (FlowPathParametersFrom2DLine).

Re: Flow Path Parameters from 2D Line Python Error

JeffreyZimmerman__Jr_ — Mon, 09 Feb 2015 17:38:22 GMT

I am still getting the same error after installing the 1/22/2015 ArcHydro 10.1 release. I also added the following code to the script, but it still gives the same error:

ArcHydroTools.SetTargetLocations("HydroConfig", "Layers", "C:\\CWUAS\\Rasters\\CWUAS", "C:\\CWUAS\\cwuas_10m.gdb")