Сводка
Возвращает объект Layer или Table для назначенного подслоя или подтаблицы указанного слоя сетевого анализа. Этот объект может быть использован в качестве входных данных для дальнейшего анализа.
Например, этот метод можно использовать для извлечения подслоя полигонов слоя анализа области обслуживания.
Примечание:
Эта функция в Python похожа на инструмент Выбрать данные в ModelBuilder.
Прежние версии:
Эта функция появилась в ArcGIS Pro 2.7. В более ранних версиях программного обеспечения лучшим способом извлечения объекта подслоя слоя сетевого анализа было использование метода listLayers объекта сетевого анализа Layer, использующего имя подслоя в качестве подстановочного знака.
Синтаксис
GetNASublayer (network_analyst_layer, naclass_name)
| Parameter | Объяснение | Тип данных | ||||||||||||
network_analyst_layer | Слой сетевого анализа, из которого требуется извлечь подслой, на который ссылаются как на объект слоя или по его имени. | Layer | ||||||||||||
naclass_name | Имя класса для извлекаемого подслоя или подтаблицы. В следующей таблице перечислены имена классов для каждого типа слоя сетевого анализа:
| String |
Пример кода
Получение подтаблицы Route Specialties для слоя задачи выбора маршрута транспорта с именем Tuesday deliveries.
tuesday = datetime.datetime(1900, 1, 2)
layer_name = "Tuesday deliveries"
vrp_layer_object = arcpy.na.MakeVehicleRoutingProblemAnalysisLayer(
"Streets_ND", layer_name, "Driving Time",
default_date=tuesday).getOutput(0)
route_specialties_table = arcpy.na.GetNASublayer(layer_name, "RouteSpecialties")В следующем автономном скрипте Python показано, как получить доступ к подслоям, соединить входные и выходные слои, и переместить значения полей из входных источников и назначений в выходной слой Линий в рабочем процессе анализа Матрицы Источник-Назначение.
# Name: MakeODCostMatrixAnalysisLayer_Workflow2.py
# Description: Find the travel time to the closest hospital from each census
# tract and join the travel time and hospital name to the input
# tracts.
# Requirements: Network Analyst Extension
# Import system modules
import datetime
import os
import arcpy
try:
# Check out Network Analyst license if available. Fail if the Network Analyst license is not available.
if arcpy.CheckExtension("network") == "Available":
arcpy.CheckOutExtension("network")
else:
raise arcpy.ExecuteError("Network Analyst Extension license is not available.")
# Set environment settings
output_dir = "C:/Data"
#The NA layer's data will be saved to the workspace specified here
arcpy.env.workspace = os.path.join(output_dir, "Output.gdb")
arcpy.env.overwriteOutput = True
# Set inputs and outputs
input_gdb = "C:/Data/SanFrancisco.gdb"
network = os.path.join(input_gdb, "Transportation", "Streets_ND")
origins = os.path.join(input_gdb, "Analysis", "TractCentroids")
destinations = os.path.join(input_gdb, "Analysis", "Hospitals")
output_features = "TractCentroids_withOD"
# Define some OD cost matrix analysis settings
layer_name = "HospitalsOD"
# User settings for driving
travel_mode = "Driving Time"
# Calculate the total distance, even though the analysis is optimizing time
accumulate_attributes = ["Meters"]
# Find only the closest hospital
num_hospitals_to_find = 1
# Set the time of day for the analysis to 6PM on a generic Monday.
start_time = datetime.datetime(1900, 1, 1, 18, 0, 0)
# Don't output line shapes (output Lines will still list travel times)
out_lines = "NO_LINES"
# Create a new OD cost matrix layer.
result_object = arcpy.na.MakeODCostMatrixAnalysisLayer(network, layer_name,
travel_mode,
number_of_destinations_to_find=num_hospitals_to_find,
time_of_day=start_time, line_shape=out_lines,
accumulate_attributes=accumulate_attributes)
# Get the layer object from the result object. The OD layer can
# now be referenced using the layer object.
layer_object = result_object.getOutput(0)
# Get the names of all the sublayers within the OD layer.
sublayer_names = arcpy.na.GetNAClassNames(layer_object)
# Store the layer names for later use
origins_layer_name = sublayer_names["Origins"]
destinations_layer_name = sublayer_names["Destinations"]
# The input census tract data has a unique ID field that can be transferred
# to the analysis layer. Add the field, and then use field mapping to
# transfer the values.
arcpy.na.AddFieldToAnalysisLayer(layer_object, origins_layer_name,
"Tract_ID", "TEXT")
field_mappings = arcpy.na.NAClassFieldMappings(layer_object,
origins_layer_name)
field_mappings["Tract_ID"].mappedFieldName = "ID"
# Load the census tracts as origins.
arcpy.na.AddLocations(layer_object, origins_layer_name, origins,
field_mappings, "")
# Map the input hospital NAME field to a new Hospital_Name field in
# Destinations
arcpy.na.AddFieldToAnalysisLayer(layer_object, destinations_layer_name,
"Hospital_Name", "TEXT")
field_mappings = arcpy.na.NAClassFieldMappings(layer_object,
destinations_layer_name)
field_mappings["Hospital_Name"].mappedFieldName = "NAME"
# Load the hospitals as desinations.
arcpy.na.AddLocations(layer_object, destinations_layer_name, destinations,
field_mappings, "")
# Solve the OD layer
arcpy.na.Solve(layer_object)
# Get sublayers
origins_sublayer = arcpy.na.GetNASublayer(layer_object, "Origins")
destinations_sublayer = arcpy.na.GetNASublayer(layer_object, "Destinations")
lines_sublayer = arcpy.na.GetNASublayer(layer_object, "ODLines")
# Use the JoinField tool to transfer OD Cost Matrix information to the
# output feature class
# Transfer the tract ID from the input Origins to the output Lines
arcpy.management.JoinField(lines_sublayer, "OriginID",
origins_sublayer, "ObjectID", "Tract_ID")
# Transfer the hospital name from the input Destinations to the output Lines
arcpy.management.JoinField(lines_sublayer, "DestinationID",
destinations_sublayer, "ObjectID", "Hospital_Name")
# Transfer fields of interest (hospital name, impedance attribute, and other
# accumulated costs) from the output Lines to a copy of the input census
# tracts feature class using the Tract_ID field
# Determine the impedance attribute
solver_props = arcpy.na.GetSolverProperties(layer_object)
impedance = solver_props.impedance
output_impedance_fieldname = "Total_" + impedance
fields_to_transfer = ["Hospital_Name", output_impedance_fieldname]
for field in accumulate_attributes:
fields_to_transfer.append("Total_" + field)
arcpy.management.CopyFeatures(origins, output_features)
arcpy.management.JoinField(output_features, "ID",
lines_sublayer, "Tract_ID", fields_to_transfer)
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 occurred on line %i" % tb.tb_lineno)
print(str(e))