Package com.luciad.network.algorithm.routing

Class TLcdCrossCountryShortestRouteAlgorithm

java.lang.Object
com.luciad.network.algorithm.routing.TLcdCrossCountryShortestRouteAlgorithm
public class TLcdCrossCountryShortestRouteAlgorithm extends Object
Implementation of a shortest route algorithm, optimized for cross country movement problems.

Cross country movement is the problem of finding the shortest route between two points in a specific area where no network (nodes and edges) is available. The area has an associated cost function defining for each two points in the area what the cost is to move from the first to the second point in a straight line.

The algorithm is based on the well-known Dijkstra algorithm, but is optimized for cross country movement.

This implementation discretizes the domain in model coordinates. All points and distance that are passed directly or indirectly (e.g. the bounds of a parameter) to an instance of this class or returned directly or indirectly (e.g. the points in the returned route) by an instance of this class are also expressed in this reference, unless explicitely stated otherwise.

Since:
9.1

  • Constructor Details

    • TLcdCrossCountryShortestRouteAlgorithm

      public TLcdCrossCountryShortestRouteAlgorithm(double aXDiscretizationStep, double aYDiscretizationStep)
      Constructs a new TLcdCrossCountryShortestRouteAlgorithm with the specified discretization.
      Parameters:
      aXDiscretizationStep - the distance in the x direction between the nodes of the discretized graph
      aYDiscretizationStep - the distance in the y direction between the nodes of the discretized graph
      Throws:
      IllegalArgumentException - if the specified x or y discretization step is ≤ 0

  • Method Details

    • getXDiscretizationStep

      public double getXDiscretizationStep()
      Returns the distance in the x direction between the nodes of the discretized graph.
      Returns:
      the distance in the x direction between the nodes of the discretized graph

    • setXDiscretizationStep

      public void setXDiscretizationStep(double aXDiscretizationStep)
      Sets the distance in the x direction between the nodes of the discretized graph.
      Parameters:
      aXDiscretizationStep - the distance in the x direction between the nodes of the discretized graph
      Throws:
      IllegalArgumentException - if the specified discretization step is ≤ 0

    • getYDiscretizationStep

      public double getYDiscretizationStep()
      Returns the distance in the y direction between the nodes of the discretized graph.
      Returns:
      the distance in the y direction between the nodes of the discretized graph

    • setYDiscretizationStep

      public void setYDiscretizationStep(double aYDiscretizationStep)
      Sets the distance in the y direction between the nodes of the discretized graph.
      Parameters:
      aYDiscretizationStep - the distance in the y direction between the nodes of the discretized graph
      Throws:
      IllegalArgumentException - if the specified discretization step is ≤ 0

    • getShortestRoute

      public ILcdRoute<ILcdPoint,ILcdPolyline> getShortestRoute(ILcdPoint aStartPoint, ILcdPoint aEndPoint, ILcdCrossCountryDistanceFunction aDistanceFunction, ILcdCrossCountryDistanceFunction aHeuristicDistanceFunction, double aMaxSearchDistance)
      Returns an ILcdRoute describing the shortest route between the start and end point.
      Parameters:
      aStartPoint - the start point.
      aEndPoint - the end point.
      aDistanceFunction - a function that computes the cost to travel from one point to another.
      aHeuristicDistanceFunction - a distance function, indicating the estimated cost to travel from one point to another. This function can be used to accelerate the search process. Note that this estimate should always be an underestimate of the real remaining distance, in order to result in an optimal solution. A heuristic function, although it can greatly increase the performance is not required for the algorithm to work - it may be null.
      aMaxSearchDistance - the maximum distance of the returned route.
      Returns:
      the shortest route between the start and end point, or null if no such route is found.
      Throws:
      IllegalArgumentException - if the start or end point is not inside the bounds of the distance function.