Network Analyst Layer properties—Help

Zusammenfassung
Eigenschaften
Codebeispiel

Zusammenfassung

The Describe function returns the following properties for Network Analyst Layers.

A Network Analyst Layer returns a dataType of "NALayer".

A Network Analyst Layer contains information about the inputs and parameters used in the analysis of a network problem using the ArcGIS Network Analyst extension.

Eigenschaften

Eigenschaft	Erläuterung	Datentyp
network (Nur lesen)	The Network Dataset object. This object can be used to get all the properties, such as catalogPath, of the underlying network dataset used by the analysis layer.	Object
nameString (Nur lesen)	The name of the Network Analyst layer.	String
solverName (Nur lesen)	The Network Analyst solver being referenced by the layer. Each layer can reference only one solver. This property returns the following keywords: Route Solver Closest Facility Solver Service Area Solver OD Cost Matrix Solver Vehicle Routing Problem Solver Location-Allocation Solver	String
impedance (Nur lesen)	The network cost attribute used as the impedance during the analysis.	String
accumulators (Nur lesen)	A semicolon-separated list of network cost attributes that are accumulated as part of the analysis.	String
restrictions (Nur lesen)	A semicolon-separated list of restriction attributes that are applied for the analysis.	String
ignoreInvalidLocations (Nur lesen)	A Boolean expression indicating the way in which the solver considers invalid network locations within the Network Analyst classes. A value of True indicates that the invalid locations are ignored by the solver. False indicates that the invalid locations are not ignored by the solver.	Boolean
uTurns (Nur lesen)	Indicates how the U-turns at junctions, which could occur during network traversal between stops, are being handled by the solver. This property returns the following keywords: ALLOW_UTURNS NO_UTURNS ALLOW_DEAD_ENDS_ONLY ALLOW_DEAD_ENDS_AND_INTERSECTIONS_ONLY	String
useHierarchy (Nur lesen)	Indicates if the Network Analyst Layer is using Hierarchy. This property returns the following keywords: USE_HIERARCHY NO_HIERARCHY	String
hierarchyAttribute (Nur lesen)	The name of the hierarchy attribute.	String
hierarchyLevelCount (Nur lesen)	The number of hierarchy ranges used to define the hierarchy attribute. The maximum value is 3.	Integer
maxValueForHierarchyX (Nur lesen)	A given hierarchy attribute can have values that define the hierarchy ranges. The maximum values for each range can be obtained from maxValueForHierarchyX property, where X indicates the hierarchy level. For example, the maximum value for the first hierarchy range (used to define the primary roads) can be obtained from the property maxValueForHierarchy1. Use the hierarchyLevelCount property to determine the possible number of maxValueForHierarchy properties for a given hierarchy attribute. For example, if the hierarchyLevelCount property returns 3, then the Describe object will support MaxValueForHierarchy1 and MaxValueForHierarchy2 properties.	Integer
locatorCount (Nur lesen)	The total number of classes that are used to search through for determining a network location.	Integer
locators (Nur lesen)	The Network Analyst Locator object. This object can be used to obtain name, snap type, and the search query information for the classes that are used for finding network locations.	Object
findClosest (Nur lesen)	Indicates how the network source features are searched when locating network analysis objects. This property returns the following keywords: MATCH_TO_CLOSEST PRIORITY	String
searchTolerance (Nur lesen)	A space-separated string indicating the search tolerance and the units used when finding the network locations.	String
excludeRestrictedElements (Nur lesen)	Indicates if the network analysis objects can be located only on traversable portions of network sources This property returns the following keywords: INCLUDE EXCLUDE	String
solverProperties (Nur lesen)	The Network Analyst Solver object. This object can be used to determine the solver-specific properties in a Network Analyst layer.	Object
children (Nur lesen)	Returns a Python List of describe objects that reference individual network analysis classes (such as stops and routes) as layers. This property cannot be used with the network analysis layer stored on disk as a layer file.	List
parameterCount (Nur lesen)	The total number of attribute parameters defined for all the network attributes of the underlying network dataset used by the Network Analyst layer.	Integer
parameters (Nur lesen)	The Network Attribute Parameter object. This object can be used to determine the attribute parameters used for the network analysis.	Object

Codebeispiel

NetworkAnalystLayer properties example

Display properties of a specified Network Analyst layer file.

# Name: NALayerProperties_ex01.py
# Description: Lists all the properties that can be derived by describing a 
#              network analysis layer.

import arcpy

#Arguments..
#in_layer is the name of the Network Analysis layer file to be described.  
in_layer = "C:/Data/Route.lyr"  

#Get the description object using Describe. 
desc = arcpy.Describe(in_layer) 

arcpy.AddMessage(" ")
arcpy.AddMessage("== Description of network analysis layer " + in_layer + " ==")
arcpy.AddMessage(" ") 

#Print general infomation.
justify = 35 
nds = desc.network 
solvername = desc.solverName 
arcpy.AddMessage("---- General information:") 
arcpy.AddMessage(" %*s: %s" % (justify, "Network" , nds.catalogPath)) 
arcpy.AddMessage(" %*s: %s" % (justify, "SolverName" , desc.solverName)) 
arcpy.AddMessage(" %*s: %s" % (justify, "Impedance" , desc.impedance)) 
arcpy.AddMessage(" %*s: %s" % (justify, "Accumulators" , desc.accumulators)) 
arcpy.AddMessage(" %*s: %s" % (justify, "Restrictions" , desc.restrictions)) 
arcpy.AddMessage(" %*s: %s" % (justify, "Ignore invalid locations?" , 
                str(desc.ignoreInvalidLocations))) 
arcpy.AddMessage(" %*s: %s" % (justify, "UTurn policy" , desc.UTurns)) 
arcpy.AddMessage(" %*s: %s" % (justify, "Using hierarchy?" , desc.useHierarchy))
arcpy.AddMessage(" %*s: %s" % (justify, "Exclude Restricted Elements?" ,
                               desc.excludeRestrictedElements))
arcpy.AddMessage(" ") 

#A note about the dynamic properties (indicated by X in the help system)
#In order to access the dynamic properties use Python's built in getattr()
#function. In order to find out if a dynamic property is supported by the 
#describe object, use Python's built in hasattr() function. 

# Print attribute parameter information
arcpy.AddMessage(" ---- Attribute Parameter information ----") 
count = desc.parameterCount 
if count == 0: 
    arcpy.AddMessage(" ---- No Attribute Parameters defined ----") 
else: 
    parameters = desc.parameters 
    for i in range(0, count): 
        attributeName = getattr(parameters,"attributeName" + str(i)) 
        parameterName = getattr(parameters, "parameterName" + str(i)) 
        parameterValue = getattr(parameters, "parameterValue" + str(i)) 
        arcpy.AddMessage(" %*s: %s: %s" % (justify, attributeName, 
                                           parameterName, parameterValue))   

# Print hierarchy information
if desc.useHierarchy.lower() == "use_hierarchy": 
    arcpy.AddMessage(" ---- Hierarchy information ----")
    arcpy.AddMessage(" %*s: %s" % (justify, "Hierarchy Attribute Name",
                                   desc.hierarchyAttribute)) 
    count = desc.hierarchyLevelCount
    arcpy.AddMessage(" %*s: %d" % (justify, "Hierarchy Level Count" , count)) 
    
    for i in range(0, count ): 
        levelRange = "" 
        if i == 0:      
            levelUB = getattr(desc,"maxValueForHierarchy" + str(i+1))            
            levelRange = "up to %s" % levelUB 
        elif i == (count - 1): 
            prevLevelUB = getattr(desc, "maxValueForHierarchy" + str(i)) 
            levelRange = "%s and higher" % (prevLevelUB + 1)
        else: 
            prevLevelUB =  getattr(desc, "maxValueForHierarchy" + str(i)) 
            levelUB = getattr(desc,"maxValueForHierarchy" + str(i + 1)) 
            levelRange = "%s - %s" % ((prevLevelUB + 1), levelUB)
        
        arcpy.AddMessage(" %*s %d range: %s" % (justify, "level", (i + 1), 
                                                levelRange))

    arcpy.AddMessage(" ") 

# Print locator information. 
arcpy.AddMessage("---- Locator information:") 
count = desc.locatorCount 
arcpy.AddMessage(" %*s: %d" % (justify, "Count" , count)) 
arcpy.AddMessage(" %*s: %s" % (justify, "Find Closest?" , desc.findClosest)) 
arcpy.AddMessage(" %*s: %s" % (justify, "Search Tolerance", 
                               desc.searchTolerance))
arcpy.AddMessage(" %*s: %s" % (justify, "Exclude Restricted Elements",
                               desc.excludeRestrictedElements))
locators = desc.locators 
for i in range(0, count): 
    sourceName = getattr(locators, "source" + str(i)) 
    sourceType = getattr(locators, "snapType" + str(i))
    searchQuery = getattr(locators, "searchQuery" + str(i))
    arcpy.AddMessage(" %*s: %s" %(justify, sourceName, sourceType))
    arcpy.AddMessage(" %*s: %s" %(justify, sourceName, searchQuery))