Package org.goplanit.algorithms.shortest

Class ShortestPathSearchUtils

  • public final class ShortestPathSearchUtils
extends Object
    Some common utilities for various shortest path algorithms. The lambdas provided base their direction (up/downstream) on the direction used in the shortest path search NOT the results it yields. To traverse the results, the opposite direciton is required which can be obtained by inverting the call via a flag.
    Author:
    markr

    • Constructor Detail

      • ShortestPathSearchUtils

        public ShortestPathSearchUtils()

    • Method Detail

      • getVertexFromEdgeSegmentLambda

        public static Function<EdgeSegment,​DirectedVertex> getVertexFromEdgeSegmentLambda​(RootedLabelledBush bush,
                                                                                        boolean invertDirection)
        Based on the bush configuration we collect different vertex direction from edge segment (up or downstream) compatible with a (shortest) path search. In case the bush is not inverted, i.e., runs from single origin to one or more destinations we collect the downstream vertex, otherwise the upstream vertex. This direction can be swapped if desired with the invertDirection parameter
        Parameters:
        bush - based on the configuration of the bush determine which vertex to collect.
        invertDirection - flag to invert direction compared to "regular" result
        Returns:
        lambda collecting vertex based on given edge segment

      • getVertexFromEdgeSegmentLambda

        public static Function<EdgeSegment,​DirectedVertex> getVertexFromEdgeSegmentLambda​(RootedLabelledBush bush)
        Based on the bush configuration we collect different vertex direction from edge segment (up or downstream) compatible with a (shortest) path search. In case the bush is not inverted, i.e., runs from single origin to one or more destinations we collect the downstream vertex, otherwise the upstream vertex.
        Parameters:
        bush - based on the configuration of the bush determine which vertex to collect.
        Returns:
        lambda collecting vertex based on given edge segment

      • getVertexFromEdgeSegmentLambda

        public static Function<EdgeSegment,​DirectedVertex> getVertexFromEdgeSegmentLambda​(ShortestSearchType shortestPathSearchType,
                                                                                        boolean invertDirection)
        Based on the search type we collect different vertex direction from edge segment (up or downstream) during shortest path search. This method provides the Lambda that performs this collection.
        Parameters:
        shortestPathSearchType - to base lambda on
        invertDirection - flag to invert direction compared to "regular" result
        Returns:
        lambda collecting vertex based on given edge segment

      • getEdgeSegmentsInDirectionLambda

        public static Function<DirectedVertex,​Iterable<? extends EdgeSegment>> getEdgeSegmentsInDirectionLambda​(RootedLabelledBush bush,
                                                                                                              boolean invertDirection)
        Based on the bush configuration we collect different edge segments from vertex (entry or exit segments) compatible with a (shortest) path search. In case the bush is not inverted, i.e., runs from single origin to one or more destinations we collect the downstream edge segments, otherwise the upstream edge segments. This direction can be swapped if desired with the invertDirection parameter
        Parameters:
        bush - to base lambda on
        invertDirection - flag to invert direction compared to "regular" result
        Returns:
        lambda collecting edge segments in given direction based on vertex provided

      • getEdgeSegmentsInDirectionLambda

        public static Function<DirectedVertex,​Iterable<? extends EdgeSegment>> getEdgeSegmentsInDirectionLambda​(RootedLabelledBush bush)
        Based on the bush configuration we collect different edge segments from vertex (entry or exit segments) compatible with a (shortest) path search. i.e., runs from single origin to one or more destinations we collect the downstream edge segments, otherwise the upstream edge segments.
        Parameters:
        bush - to base lambda on
        Returns:
        lambda collecting edge segments in given direction based on vertex provided

      • getEdgeSegmentsInDirectionLambda

        public static Function<DirectedVertex,​Iterable<? extends EdgeSegment>> getEdgeSegmentsInDirectionLambda​(ShortestSearchType shortestPathSearchType)
        Based on the search type we collect edge segments (up or downstream) for a given vertex. This method provides the Lambda that performs this collection.
        Parameters:
        shortestPathSearchType - to base lambda on
        Returns:
        lambda collecting edge segments in given direction based on vertex provided

      • getEdgeSegmentsInDirectionLambda

        public static Function<DirectedVertex,​Iterable<? extends EdgeSegment>> getEdgeSegmentsInDirectionLambda​(ShortestSearchType shortestPathSearchType,
                                                                                                              boolean invertDirection)
        Based on the search type we collect edge segments (up or downstream) for a given vertex. This method provides the Lambda that performs this collection.
        Parameters:
        shortestPathSearchType - to base lambda on
        invertDirection - flag to invert direction compared to "regular" result
        Returns:
        lambda collecting edge segments in given direction based on vertex provided