Solve (Network Analyst)
Summary
Solves the network analysis layer problem based on its network locations and properties.
Usage
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When the solve fails, the warning and error messages provide useful information about the reasons for the failure.
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Be sure to specify all the parameters on the network analysis layer that are necessary to solve the problem before running this tool.
Syntax
Parameter | Explanation | Data Type |
in_network_analysis_layer |
The network analysis layer on which the analysis will be computed. | Network Analyst Layer |
ignore_invalids (Optional) |
For vehicle routing problem network analysis layer, use HALT as the parameter value since the vehicle routing problem solver requires all the network locations to be valid. | Boolean |
terminate_on_solve_error (Optional) |
| Boolean |
Code Sample
Execute the tool using all the parameters.
import arcpy arcpy.Solve_na("Route","HALT","TERMINATE")
The following stand-alone Python script demonstrates how the Solve tool can be used to perform a closest facility analysis and save results to a layer file.
# Name: Solve_Workflow.py # Description: Solve a closest facility analysis to find the closest warehouse # from the store locations and save the results to a layer file on # disk. # Requirements: Network Analyst Extension # Author: ESRI #Import system modules import arcpy from arcpy import env try: #Check out the Network Analyst extension license arcpy.CheckOutExtension("Network") #Set environment settings env.workspace = "C:/data/Paris.gdb" env.overwriteOutput = True #Set local variables inNetworkDataset = "Transportation/ParisMultimodal_ND" outNALayer = "ClosestWarehouse" impedanceAttribute = "Drivetime" accumulateAttributeName = ["Meters"] inFacilities = "Analysis/Warehouses" inIncidents = "Analysis/Stores" fieldMappings = "Name NOM #" outLayerFile = "C:/data/output" + "/" + outNALayer + ".lyr" #Create a new closest facility analysis layer. Apart from finding the drive #time to the closest warehouse, we also want to find the total distance. So #we will accumulate the "Meters" impedance attribute. arcpy.MakeClosestFacilityLayer_na(inNetworkDataset,outNALayer, impedanceAttribute,"TRAVEL_TO","",1, accumulateAttributeName,"NO_UTURNS") #Load the warehouses as Facilities using the default field mappings and #search tolerance arcpy.AddLocations_na(outNALayer,"Facilities",inFacilities,"","") #Load the Stores as Incidents. Map the Name property from the NOM field arcpy.AddLocations_na(outNALayer,"Incidents",inIncidents,fieldMappings,"") #Solve the closest facility layer arcpy.Solve_na(outNALayer) #Save the solved closest facility layer as a layer file on disk using #relative paths arcpy.SaveToLayerFile_management(outNALayer,outLayerFile,"RELATIVE") print "Script completed successfully" except Exception as e: # If an error occurred, print line number and error message import traceback, sys tb = sys.exc_info()[2] print "An error occured on line %i" % tb.tb_lineno print str(e)