createSingleDirectionNetwork

Create Single Directional Network

Creates from a polyline dataset a Single Derectional Network. This is a network in which travel is allowed only in one direction. The default direction is in the physical direction of the input polylines. This however might be changed for specific edges by the attributes in the "Direction" field in the attribute table of the input dataset.

Inputs:

A polyline feature layer
Direction filed which values define the direction of travel for each edge. This is optional parameter. The default is that travel is allowed in the physical direction of the input polyline.

Two Elevation fileds which values define the relative elevation of the start and end node of each edge.
A Cost filed which values defines the cost of travel for each edge. This is an optional parameter. The default cost of travel is the length of the polyline represented by this link.

Outputs:

A Network stored in a single file with .etn extension

Notes :

After the network is created it is not dependent on the source layer from which it was created. It however keeps a reference to the source file which is important for the analysis.
If you edit the source polyline layer, you need to rebuild the Network in order the changes to be reflected in the consequent analysis.

Running Programmatically

(Go to TOP)

Parameters

Expression	Explanation
Function Name	BuildSingleDirectionalNetwork
<input dataset>	A String representing the input layer. Must be of Polyline type.
<output network>	A String - the full name of the output layer.
{Direction Field}	A String representing the Name of the field defining the Direction. If not specified travel in the physical direction of the input polylines is allowed. Valid values: "FT" (meaning From => To ) - traveling along the direction of the polyline is allowed. "TF" (meaning To => From ) - traveling against the direction of the polyline is allowed. "N" - No traveling is allowed. All other strings mean that traveling in the physical direction of the input polylines is allowed.
{From Level Field}	A String representing the Name of the field defining the elevation of the FROM Node of the polylines. If not specified a level of 1 will be set for the FROM Nodes of all edges.
{To Level Field}	A String representing the Name of the field defining the elevation of the TO Node of the polylines. If not specified a level of 1 will be set for the TO Nodes of all edges.
{Cost Field}	A String representing the Name of the field defining the cost of the edge. If not specified the cost for all edges will be the length of the corresponding polylines.

Running the function

ETGWPath used in the table below is the full path to ETGWRun.exe (E.G. "C:\Program Files\ETSpatial Techniques\ETGeo Wizards\ETGWRun.exe")

Language	Syntax
Python	subprocess.call([ETGWPath, "BuildSingleDirectionalNetwork", "input dataset", "output network", "Direction Field", "From Level Field" "To Level Field" "Cost Field"])
.NET using ETGWRun.exe	StartInfo.FileName = ETGWPath StartInfo.Arguments = "BuildSingleDirectionalNetwork" "input dataset" "output network" "Direction Field" "From Level Field" "To Level Field" "Cost Field"
.NET using ETGWOutX.dll	BuildSingleDirectionalNetwork(input dataset, output network, Direction Field, From Level Field,To Level Field, Cost Field )
ArcPy	arcpy.BuildSingleDirectionalNetwork(input dataset, output network, "Direction Field", "From Level Field", "To Level Field", "Cost Field")

Notes:

<> - required parameter
{} - optional parameter
See examples for Python , .NET or ArcPy
The argument separator for StartInfo.Arguments is space. If a string might contain a space, you need to double quote it.

(Go to TOP)