Ejemplo n.º 1
0
  /* computes the distance, in meters, along a geometry */
  protected static double distanceAlongGeometry(
      Geometry geometry, LinearLocation startIndex, LinearLocation endIndex) {

    if (endIndex == null) {
      endIndex = LinearLocation.getEndLocation(geometry);
    }
    double total = 0;
    LinearIterator it = new LinearIterator(geometry, startIndex);
    LinearLocation index = startIndex;
    Coordinate previousCoordinate = startIndex.getCoordinate(geometry);

    it.next();
    index = it.getLocation();
    while (index.compareTo(endIndex) < 0) {
      Coordinate thisCoordinate = index.getCoordinate(geometry);
      double distance = SphericalDistanceLibrary.fastDistance(previousCoordinate, thisCoordinate);
      total += distance;
      previousCoordinate = thisCoordinate;
      if (!it.hasNext()) break;
      it.next();
      index = it.getLocation();
    }
    // now, last bit of last segment
    Coordinate finalCoordinate = endIndex.getCoordinate(geometry);
    total += SphericalDistanceLibrary.distance(previousCoordinate, finalCoordinate);

    return total;
  }
Ejemplo n.º 2
0
 /**
  * FIXME OBA parentStation field is a string, not an AgencyAndId, so it has no agency/feed scope
  * But the DC regional graph has no parent stations pre-defined, so no use dealing with them for
  * now. However Trimet stops have "landmark" or Transit Center parent stations, so we don't use
  * the parent stop field.
  *
  * <p>Ideally in the future stop clusters will replicate and/or share implementation with GTFS
  * parent stations.
  *
  * <p>We can't use a similarity comparison, we need exact matches. This is because many street
  * names differ by only one letter or number, e.g. 34th and 35th or Avenue A and Avenue B.
  * Therefore normalizing the names before the comparison is essential. The agency must provide
  * either parent station information or a well thought out stop naming scheme to cluster stops --
  * no guessing is reasonable without that information.
  */
 public void clusterStops() {
   int psIdx = 0; // unique index for next parent stop
   LOG.info("Clustering stops by geographic proximity and name...");
   // Each stop without a cluster will greedily claim other stops without clusters.
   for (Stop s0 : stopForId.values()) {
     if (stopClusterForStop.containsKey(s0))
       continue; // skip stops that have already been claimed by a cluster
     String s0normalizedName = StopNameNormalizer.normalize(s0.getName());
     StopCluster cluster = new StopCluster(String.format("C%03d", psIdx++), s0normalizedName);
     // LOG.info("stop {}", s0normalizedName);
     // No need to explicitly add s0 to the cluster. It will be found in the spatial index query
     // below.
     Envelope env = new Envelope(new Coordinate(s0.getLon(), s0.getLat()));
     env.expandBy(
         SphericalDistanceLibrary.metersToLonDegrees(CLUSTER_RADIUS, s0.getLat()),
         SphericalDistanceLibrary.metersToDegrees(CLUSTER_RADIUS));
     for (TransitStop ts1 : stopSpatialIndex.query(env)) {
       Stop s1 = ts1.getStop();
       double geoDistance =
           SphericalDistanceLibrary.fastDistance(
               s0.getLat(), s0.getLon(), s1.getLat(), s1.getLon());
       if (geoDistance < CLUSTER_RADIUS) {
         String s1normalizedName = StopNameNormalizer.normalize(s1.getName());
         // LOG.info("   --> {}", s1normalizedName);
         // LOG.info("       geodist {} stringdist {}", geoDistance, stringDistance);
         if (s1normalizedName.equals(s0normalizedName)) {
           // Create a bidirectional relationship between the stop and its cluster
           cluster.children.add(s1);
           stopClusterForStop.put(s1, cluster);
         }
       }
     }
     cluster.computeCenter();
     stopClusterForId.put(cluster.id, cluster);
   }
   //        LOG.info("Done clustering stops.");
   //        for (StopCluster cluster : stopClusterForId.values()) {
   //            LOG.info("{} at {} {}", cluster.name, cluster.lat, cluster.lon);
   //            for (Stop stop : cluster.children) {
   //                LOG.info("   {}", stop.getName());
   //            }
   //        }
 }
Ejemplo n.º 3
0
 protected static double distance(Coordinate from, Coordinate to) {
   return SphericalDistanceLibrary.fastDistance(from, to);
 }