Line Coverage To Route (Coverage)

Summary

Creates a route system by creating whole arc sections for each arc in the input coverage and can also be used to append arcs to an existing route system.

Usage

• Creates a route system from lines or appends lines to a route system. It groups lines that are topologically connected and have unique values for the Input item to create the route system. The unique values of the Input item are always written to the Output item in the route attribute table (RAT); these values help identify routes once they have been created.

• When appending routes to an existing route system, the Output Route Item must be the name of an existing item on the route attribute table of the route system. The tool will append a section to an existing route for every input arc having an Input item equal to an Output Route Item in the route attribute table, provided the input arcs are topologically connected to the route being appended. The Measure Item on the original part of the route being appended is updated based on the measures assigned to the new sections and the specified Starting node. For those groups of arcs having values for the Input Route Item not found in the Output Route Item, a new route is created.

• Line Coverage To Route groups arcs into routes based on both the unique values in the Input Route Item and the topological connectivity of the arcs. Line Coverage To Route cannot be used to group topologically disjointed sets of arcs into the same route based on the Input Route Item.

• If the Input Route Item is a floating point, then it is truncated to integer for building the routes in the new route-system.

• Line Coverage To Route will merge two or more routes if they have the same value for the Output Route Item and become connected due to arcs being appended.

• Line Coverage To Route will not append a section to an existing route if the existing route contains overlapping sections. The input arcs are assigned to a new route instead.

• The unique values in the Input Route Item are always written to the Output Route Item in the route attribute table. Use the values in the Output Route Item to help you identify routes once they have been created.

• The Input Cover must have an arc attribute table, and node numbers must exist and be up-to-date. Use Build with the LINE option to create or update an arc attribute table. Use Renumber Node to update node numbers.

• When using the Create Route From Null Values, note that the BLANK option is considered to be zero (0.0) or null where the Input Route Item is numeric, and null where the Input Route Item is character. The Create Route From Null ValuesBLANK option is not considered if the Input Route Item is not specified.

Syntax

ArcRoute_arc (in_cover, out_route_system, {in_route_item}, {out_route_item}, {measure_item}, {coordinate_priority}, {use_blanks})

Parameter	Explanation	Data Type
in_cover	The coverage from which the routes are to be created.	Coverage
out_route_system	The name of the route system to be created or appended.	String
in_route_item (Optional)	The name of an item in the arc attribute table used to group arcs into separate routes. A new route is created in the route attribute table for each unique value in this item. The default is to create a route for each topologically connected set of arcs.	ArcInfo Item
out_route_item (Optional)	The name of the new item in the route attribute table that will contain the unique values in the input route item. When appending routes to an existing route system, it is an existing item in the route attribute table used to append routes. The default item is Input Route Item.	String
measure_item (Optional)	An item in the arc attribute table of Input Coverage whose value is accumulated to produce the measure values. The default item is LENGTH.	ArcInfo Item
coordinate_priority (Optional)	Determines coordinate priority when choosing a start node for the route. UL —Upper left. This is the default. UR —Upper right. LL —Lower left. LR —Lower right.	String
use_blanks (Optional)	Specifies whether arcs having a null or 0 value for the input route item will be used to create a route. BLANK —Arcs having a null or 0 value for the Input Route Item will be used to create routes. This is the default. NOBLANK —Arcs having a null or 0 value for the Input Route Item will not be used to create routes.	Boolean

Code Sample

ArcRoute example (stand-alone script)

The following stand-alone script demonstrates how to create a route system for a line coverage that contains road segments.

# Name: ArcRoute_Example.py
# Description: Adds a route system to a streams coverage
# Requirements: ArcInfo Workstation
# Author: ESRI

# Import system modules
import arcpy
from arcpy import env

# Set environment settings
env.workspace = "C:/data"

# Set local variables
inCover = "stream"
outRouteSystem = "nstreams"
inRouteItem = "STREAM_NAME"
coordinatePriority = "LL"
useBlanks = "NO_BLANK"

# Execute ArcRoute
arcpy.ArcRoute_arc(inCover, outRouteSystem, inRouteItem, "", "", 
                   coordinatePriority, useBlanks)

Environments

Current Workspace, Level Of Comparison Between Projection Files, Precision For Derived Coverages, Precision For New Coverages, Scratch Workspace

Licensing Information

ArcView: No

ArcEditor: No

ArcInfo: Requires ArcInfo Workstation installed