需要 Network Analyst 许可。
摘要
基于网络位置和属性求解网络分析图层问题。
用法
求解失败时,警告和错误消息可提供有关失败原因的有用信息。
运行此工具前,请确保为网络分析图层指定了求解问题所需的所有参数。
语法
Solve_na (in_network_analysis_layer, {ignore_invalids}, {terminate_on_solve_error}, {simplification_tolerance})
参数 | 说明 | 数据类型 |
in_network_analysis_layer | 要进行分析计算的网络分析图层。 | Network Analyst Layer |
ignore_invalids (可选) |
| Boolean |
terminate_on_solve_error (可选) |
| Boolean |
simplification_tolerance (可选) | 容差确定输出几何的简化程度。如果已指定了容差,容差必须大于零。可以选择首选单位;默认单位为十进制度。 指定简化容差会减少渲染路径或服务区的时间。但缺点是,简化几何移除了折点,这样会降低以更大比例输出的空间精确度。 由于带两个折点的线不能再简化,所以此参数对单一线段输出的绘制时间没有影响,例如直线路线、 OD 成本矩阵线和位置分配线。 | Linear unit |
代码实例
求解示例 1(Python 窗口)
使用所有参数执行工具。
arcpy.na.Solve("Route", "HALT", "TERMINATE", "10 Meters")
求解示例 2(工作流)
以下独立 Python 脚本演示了如何使用“求解”工具执行最近设施点分析并将结果保存到图层文件中。
# 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
#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"
outNALayerName = "ClosestWarehouse"
impedanceAttribute = "Drivetime"
accumulateAttributeName = ["Meters"]
inFacilities = "Analysis/Warehouses"
inIncidents = "Analysis/Stores"
outLayerFile = "C:/data/output" + "/" + outNALayerName + ".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.
outNALayer = arcpy.na.MakeClosestFacilityLayer(inNetworkDataset,outNALayerName,
impedanceAttribute,"TRAVEL_TO",
"",1, accumulateAttributeName,
"NO_UTURNS")
#Get the layer object from the result object. The closest facility layer can
#now be referenced using the layer object.
outNALayer = outNALayer.getOutput(0)
#Get the names of all the sublayers within the closest facility layer.
subLayerNames = arcpy.na.GetNAClassNames(outNALayer)
#Stores the layer names that we will use later
facilitiesLayerName = subLayerNames["Facilities"]
incidentsLayerName = subLayerNames["Incidents"]
#Load the warehouses as Facilities using the default field mappings and
#search tolerance
arcpy.na.AddLocations(outNALayer, facilitiesLayerName, inFacilities, "", "")
#Load the Stores as Incidents. Map the Name property from the NOM field
#using field mappings
fieldMappings = arcpy.na.NAClassFieldMappings(outNALayer, incidentsLayerName)
fieldMappings["Name"].mappedFieldName = "NOM"
arcpy.na.AddLocations(outNALayer, incidentsLayerName, inIncidents,
fieldMappings,"")
#Solve the closest facility layer
arcpy.na.Solve(outNALayer)
#Save the solved closest facility layer as a layer file on disk with
#relative paths
arcpy.management.SaveToLayerFile(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)
环境
许可信息
- ArcGIS for Desktop Basic: 需要 Network Analyst
- ArcGIS for Desktop Standard: 需要 Network Analyst
- ArcGIS for Desktop Advanced: 需要 Network Analyst