Table of Contents
TGIS_ShortestPath class
DK11 for Java | tatukgis.jdk.TGIS_ShortestPath | Classes | Constructors | Fields | Methods | Properties | Events
Encapsulation of shortest path algorithm.
Syntax
// Java public class TGIS_ShortestPath extends TGIS_BaseObjectDisposable { };
// Oxygene type TGIS_ShortestPath = public class( TGIS_BaseObjectDisposable ) end;
Inheritance
→ TGIS_BaseObjectDisposable
Constructors
| Name | Visibility | Description | |
|---|---|---|---|
| TGIS_ShortestPath() | public | Create an instance. | |
Fields
| Name | Visibility | Description | |
|---|---|---|---|
| FOnLinkCost | protected | Event which will be fired upon creating a network. | |
| FOnLinkDynamic | protected | Event which will be fired upon traversing link. | |
| FOnLinkLevel | protected | Event which will be fired upon getting the level of the endings of each link. | |
| FOnLinkType | protected | Event which will be fired upon getting the type of each link. | |
| FOnNodeHeuristicCost | protected | Event which will be fired upon calculation of heuristic cost. | |
| FOnPath | protected | Event which will be fired on each link of the discovered shortest path. | |
Methods
| Name | Visibility | Description | |
|---|---|---|---|
| Find | public | Find path between two existing nodes. | |
| LoadTheData | public | Load data from the layer. | |
| Regenerate | public | Recreate network (including network storage files). | |
| StartPos | public | Set a start position for the shortest path. | |
| StopPos | public | Set a stop position for the shortest path and run shortest path. | |
| UpdateTheData | public | Update the data with geocoded addresses from geocoder | |
Properties
| Name | Visibility | Description | |
|---|---|---|---|
| CompassBlocks | public | Compass divided to a number of blocks (4 by default). | |
| CostModifiers | public | Cost modifier. | |
| Extent | public | Path extent. | |
| HeuristicCostModifier | public | Heuristic cost modifier. | |
| HeuristicMode | public | Mode of heuristic operation. | |
| HeuristicThreshold | public | Threshold of starting node seeking area. | |
| Items | public | Items in the shortest path. | |
| ItemsCount | public | Number of items in the shortest path. | |
| Layer | public | Layer assigned to the shortest path. | |
| Network | public | Instance of Network class (responsible for low level network operations) | |
| OSMRouting | public | If true the local routing resource is ignored and the requests are send to the TatukGIS online routing service. | |
| RoadLength | public | Field name used to calculate segment length. | |
| RoadName | public | Field for the feature name. | |
| StoragePath | public | Forced storage path. | |
| TotalCost | public | Total cost of the path. | |
Events
| Name | Visibility | Description | |
|---|---|---|---|
| LinkCostEvent | public | Event which will be fired upon creating a network. | |
| LinkDynamicEvent | public | Event which will be fired upon traversing link. | |
| LinkLevelEvent | public | Event which will be fired upon getting the level of the endings of each link. | |
| LinkTypeEvent | public | Event which will be fired upon getting the type of each link. | |
| NodeHeuristicCostEvent | public | Event which will be fired upon calculation of heuristic cost. | |
| PathEvent | public | Event which will be fired on each link of the discovered shortest path. | |
Remarks
Types of routing functionality supported by the DK are as follows:
- Link cost (for each direction separately)
- Link cost modifier to reflect personal preferences.
Typical examples are “time to traverse” and length/distance“ based. For a pipeline network, the cost might be based on volume throughput. The cost is reflected in the vector parameters/attributes.
- On demand link cost calculation. This would calculate the cost individually on each call for situations when parameters are changing dynamically. An example might be an electrical power network grid.
- Cost for traversing a node. An example might be to consider the economic cost of a toll bridge/road, or the vehicle maintenance cost associated with a particularly poorly maintained segment of road.
Basic geocoding delivers the estimated position of each street number based on the known first and last street addresses on each side of each block or each street. Locations can also be searched based on street crossings.
As is normal for GIS, all street address locations are referenced to a geographic coordinate space, so that the geocoding application can be combined with other GIS functionalities, such as GPS tracking, etc.
Data are loaded from a shape and nodes are constructed on-line. If you want to support unidirectional street routing then attach negative cost. Node cost traverse methodology is not supported. Node UID can be stored in a layer under the name NodeA, NodeB and must be an integer value greater than 0.