Java Code Examples for org.matsim.core.network.NetworkUtils#getNearestNodes()

/**
 * Looks for nodes within search radius of <tt>coord</tt> (using {@link NetworkUtils#getNearestNodes},
 * fetches all in- and outlinks and sorts them ascending by their
 * distance to the coordinates given. A map with the distance as key and a set as value is used
 * to (1) return the already calculated distance to the coord and (2) store two opposite links under
 * the same distance.
 *
 * @param network               The network
 * @param coord                 the coordinate from which the closest links are
 *                              to be searched
 * @param nodeSearchRadius      Only links from and to nodes within this radius are considered.
 * @param allowedTransportModes Only links with at least one of these transport modes are considered. All links are considered if <tt>null</tt>.
 */
 public static Map<Double, Set<Link>> findClosestLinks(Network network, Coord coord, double nodeSearchRadius, Set<String> allowedTransportModes) {
	 Collection<Node> nearestNodes = NetworkUtils.getNearestNodes(network, coord, nodeSearchRadius);
	 SortedMap<Double, Set<Link>> closestLinksSortedByDistance = new TreeMap<>();

	 if(nearestNodes.size() != 0) {
		 // fetch every in- and outlink of each node
		 HashSet<Link> links = new HashSet<>();
		 for(Node node : nearestNodes) {
			 links.addAll(node.getOutLinks().values());
			 links.addAll(node.getInLinks().values());
		 }

		 // calculate lineSegmentDistance for all links
		 for(Link link : links) {
			 // only use links with a viable network transport mode
			 if(allowedTransportModes == null || MiscUtils.collectionsShareMinOneStringEntry(link.getAllowedModes(), allowedTransportModes)) {
				 double lineSegmentDistance = CoordUtils.distancePointLinesegment(link.getFromNode().getCoord(), link.getToNode().getCoord(), coord);
				 MapUtils.getSet(lineSegmentDistance, closestLinksSortedByDistance).add(link);
			 }
		 }
	 }
	 return closestLinksSortedByDistance;
}
 

/**
 * Returns the nearest link for the given coordinate.
 * Looks for nodes within search radius of coord (using {@link NetworkUtils#getNearestNodes},
 * fetches all in- and outlinks returns the link with the smallest distance
 * to the given coordinate. If there are two opposite links, the link with
 * the coordinate on its right side is returned.<p/>
 *
 * NOTE: In contrast to {@link NetworkUtils#getNearestLink}, this method looks for the
 * nearest link passing the coordinate from a reasonable set of nearby nodes instead
 * of the closest link originating from or ending in the closest node.
 *
 * @param network network
 * @param coord   the coordinate
 * @param nodeSearchRadius links from/to nodes within this radius are considered
 */
public static Link getNearestLink(Network network, Coord coord, double nodeSearchRadius) {
	Link closestLink = null;
	double minDistance = Double.MAX_VALUE;

	Collection<Node> nearestNodes = NetworkUtils.getNearestNodes(network, coord, nodeSearchRadius);

	while(nearestNodes.size() == 0) {
		nodeSearchRadius *= 2;
		nearestNodes = NetworkUtils.getNearestNodes(network, coord, nodeSearchRadius);
	}
	// check every in- and outlink of each node
	for(Node node : nearestNodes) {
		Set<Link> links = new HashSet<>(node.getOutLinks().values());
		links.addAll(node.getInLinks().values());
		double lineSegmentDistance;

		for(Link link : links) {
			// only use links with a viable network transport mode
			lineSegmentDistance = CoordUtils.distancePointLinesegment(link.getFromNode().getCoord(), link.getToNode().getCoord(), coord);

			if(lineSegmentDistance < minDistance) {
				minDistance = lineSegmentDistance;
				closestLink = link;
			}

		}
	}

	// check for opposite link
	Link oppositeLink = getOppositeLink(closestLink);
	if(oppositeLink != null && !coordIsOnRightSideOfLink(coord, closestLink)) {
		return oppositeLink;
	} else {
		return closestLink;
	}
}