4.6 Networks

GIS vector data (3.2) in MicroCity can be topologized to Networks and applied the Shortest Path Algorithm and User Equilibrium Traffic Assignment Algorithm. Sample codes for this chapter can be found in the "network_samples" folder of the Project Tab in ScriptEditor.

Network Manipulation

CreateNetwork ()

Creates an empty network and returns the object.

CreateNetwork (UnTopoLines)

Creates a network from an untopologized "line" Shapes and returns three objects: Network, Nodes (Shapes) and Links (Shapes).

CreateNetwork (Nodes, Links)

Creates a Network object from topologized Nodes and Links Shapes. Returns the Network object.

InitNetwork (Network, Nodes, Links)

Initiates a Network from a Nodes and a Links Shapes. Returns true if succeed.

AddLink (Network, linkID|-1, oID|-1, dID|-1, impedance [, direction = 1 [, capacity = 1E+38]])

Adds a new link or update an existing link in the Network. Returns linkID, oID, dID, true/false for adding and true/false for updating.

AddLink (Network, Shapes|Table, index1 [, index2, ...])

Adds or updates links from the recordset of a Shapes or Table. Returns boolean values.

DelLink (Network, linkID)

Deletes a link from a Network. Returns a boolean value.

GetNearNodeID (Network, x, y [, radius=nil])

Gets the nearest Network nodes from a coordinate. Returns node ids.

GetNodeXY (Network, nodeID1 [, nodeID2, ...])

Returns the coordinates of nodes in a Network: x1, y1, x2, y2, ... .

Algorithms

GenSTPTree (Network, startID [, endID])

Generates a Shortest Path Spanning Tree from a node. Returns a boolean value.

GetSTPPath (Network, endID, "NodeID"|"LinkID")

After calling GenSTPTree calls this function. Returns a Shortest Path indicated by a node or link id sequence: id1, id2 ,... .

GetSTPPath (Network, endID, "iNodeShp"|"iLinkShp")

After calling GenSTPTree calls this function. Returns a Shortest Path indicated by a node or link Shapes index sequence.

GetSTPPath (Network, endID, "NodeShp"|"LinkShp")

After calling GenSTPTree calls this function. Returns a Shortest Path indicated by a node or link Shape object sequence.

GetSTPLen (Network, endID)

After calling GenSTPTree call this function. Returns a Shortest Path Distance to a end node.

GetSTPLen (Network, startID, endID)

Gets a Shortest Path from a start node to an end node in a Network. Returns the distance.

GetSTPLen (Network, x1, y1, x2, y2)

Gets a Shortest Path from a start coordinate to an end coordinate in a Network. Returns the distance.

SetTrip (Network, oID, dID, amount)

Sets an amount of a trip from an origin to an destination.

SolveUE (Network [, rootTol = 1E-2 [, equlBrm = 1E-5 [, maxIter = 10000]]])

After calling SetTrip call this function. Performs the User Equilibium Traffic Assignment and returns a boolean value.

GetFlow (Network, linkID)

Returns the traffic flow of a specified link.

SetFlow (Network, linkID, flow)

Set the traffic flow of a specified link and return a boolean value.