@Override
protected Set<Tuple<MatcherCandidate, Double>> candidates(
Set<MatcherCandidate> predecessors, MatcherSample sample) {
if (logger.isTraceEnabled()) {
logger.trace(
"finding candidates for sample {} {}",
new SimpleDateFormat("yyyy-MM-dd HH:mm:ssZ").format(sample.time()),
GeometryEngine.geometryToWkt(sample.point(), WktExportFlags.wktExportPoint));
}
Set<RoadPoint> points_ = map.spatial().radius(sample.point(), radius);
Set<RoadPoint> points = new HashSet<RoadPoint>(Minset.minimize(points_));
Map<Long, RoadPoint> map = new HashMap<Long, RoadPoint>();
for (RoadPoint point : points) {
map.put(point.edge().id(), point);
}
for (MatcherCandidate predecessor : predecessors) {
RoadPoint point = map.get(predecessor.point().edge().id());
if (point != null && point.fraction() < predecessor.point().fraction()) {
points.remove(point);
points.add(predecessor.point());
}
}
Set<Tuple<MatcherCandidate, Double>> candidates =
new HashSet<Tuple<MatcherCandidate, Double>>();
logger.debug("{} ({}) candidates", points.size(), points_.size());
for (RoadPoint point : points) {
double dz = spatial.distance(sample.point(), point.geometry());
double emission = 1 / sqrt_2pi_sig2 * Math.exp((-1) * dz / (2 * sig2));
MatcherCandidate candidate = new MatcherCandidate(point);
candidates.add(new Tuple<MatcherCandidate, Double>(candidate, emission));
logger.trace("{} {} {}", candidate.id(), dz, emission);
}
return candidates;
}
@Override
protected Map<MatcherCandidate, Map<MatcherCandidate, Tuple<MatcherTransition, Double>>>
transitions(
final Tuple<MatcherSample, Set<MatcherCandidate>> predecessors,
final Tuple<MatcherSample, Set<MatcherCandidate>> candidates) {
if (logger.isTraceEnabled()) {
logger.trace(
"finding transitions for sample {} {} with {} x {} candidates",
new SimpleDateFormat("yyyy-MM-dd HH:mm:ssZ").format(candidates.one().time()),
GeometryEngine.geometryToWkt(candidates.one().point(), WktExportFlags.wktExportPoint),
predecessors.two().size(),
candidates.two().size());
}
Stopwatch sw = new Stopwatch();
sw.start();
final Set<RoadPoint> targets = new HashSet<RoadPoint>();
for (MatcherCandidate candidate : candidates.two()) {
targets.add(candidate.point());
}
final AtomicInteger count = new AtomicInteger();
final Map<MatcherCandidate, Map<MatcherCandidate, Tuple<MatcherTransition, Double>>>
transitions =
new ConcurrentHashMap<
MatcherCandidate, Map<MatcherCandidate, Tuple<MatcherTransition, Double>>>();
final double base =
1.0 * spatial.distance(predecessors.one().point(), candidates.one().point()) / 60;
final double bound =
Math.max(
1000d,
Math.min(
distance, ((candidates.one().time() - predecessors.one().time()) / 1000) * 100));
InlineScheduler scheduler = StaticScheduler.scheduler();
for (final MatcherCandidate predecessor : predecessors.two()) {
scheduler.spawn(
new Task() {
@Override
public void run() {
Map<MatcherCandidate, Tuple<MatcherTransition, Double>> map =
new HashMap<MatcherCandidate, Tuple<MatcherTransition, Double>>();
Stopwatch sw = new Stopwatch();
sw.start();
Map<RoadPoint, List<Road>> routes =
router.route(predecessor.point(), targets, cost, new Distance(), bound);
sw.stop();
logger.trace("{} routes ({} ms)", routes.size(), sw.ms());
for (MatcherCandidate candidate : candidates.two()) {
List<Road> edges = routes.get(candidate.point());
if (edges == null) {
continue;
}
Route route = new Route(predecessor.point(), candidate.point(), edges);
// According to Newson and Krumm 2009, transition probability is lambda *
// Math.exp((-1.0) * lambda * Math.abs(dt - route.length())), however, we
// experimentally choose lambda * Math.exp((-1.0) * lambda * Math.max(0,
// route.length() - dt)) to avoid unnecessary routes in case of u-turns.
double beta =
lambda == 0
? (2.0
* Math.max(1d, candidates.one().time() - predecessors.one().time())
/ 1000)
: 1 / lambda;
double transition =
(1 / beta)
* Math.exp(
(-1.0) * Math.max(0, route.cost(new TimePriority()) - base) / beta);
map.put(
candidate,
new Tuple<MatcherTransition, Double>(new MatcherTransition(route), transition));
logger.trace(
"{} -> {} {} {} {}",
predecessor.id(),
candidate.id(),
base,
route.length(),
transition);
count.incrementAndGet();
}
transitions.put(predecessor, map);
}
});
}
if (!scheduler.sync()) {
throw new RuntimeException();
}
sw.stop();
logger.trace("{} transitions ({} ms)", count.get(), sw.ms());
return transitions;
}