private void ReduceResult(PublicTransportResult result, int count)
{
// find intersection bubbles
for (int i = 0; i < Math.Min(count, result.Items.Count); i++)
{
var radiusKmBig = WalkingKmh * result.Items[i].TimeLeft / 60;
for (int j = i + 1; j < result.Items.Count; j++)
{
var radiusKm = WalkingKmh * result.Items[j].TimeLeft / 60;
if ((radiusKmBig - radiusKm) * (radiusKmBig - radiusKm) > result.Items[j].Center.DistanceInKmSquaredTo(result.Items[i].Center))
{
result.Items.RemoveAt(j);
j--;
}
}
}
}
private PublicTransportResult Calculate(LatLng startPosition, double maxTime, List <TravelTimeListPoint> points = null)
{
var stopQueue = new PriorityQueue <TravelTimeAlgorithmItem>();
var stopList = new Dictionary <int, TravelTimeAlgorithmItem>();
// start search
var startItem = new TravelTimeAlgorithmItem {
Stop = new PublicTransportConnection()
{
LatLng = startPosition, Cost = 0, ID = 0
}, TotalCost = 0
};
stopQueue.Enqueue(startItem, 0);
stopList[0] = startItem;
while (stopQueue.Count > 0)
{
var stop = stopQueue.Dequeue();
if (stop.TotalCost >= maxTime)
{
break;
}
double timeLeft = maxTime - stop.TotalCost;
List <PublicTransportConnection> reachableStops;
if (stop.Stop.ID > 0)
{
reachableStops = _dataProvider.GetReachableByTransport(stop.Stop.ID, timeLeft);
}
else
{
// calculate approximate radius - its not exact as lat/lng circle cant be a perfect circle
double radius = LatLng.GetWalkingDistanceLatLng(startPosition.Lat, maxTime, WalkingKmh);
reachableStops = _dataProvider.GetInRange(startPosition, radius);
}
foreach (var reachableStop in reachableStops)
{
double newTotalCost = stop.TotalCost + reachableStop.Cost;
TravelTimeAlgorithmItem existingStop;
if (stopList.TryGetValue(reachableStop.ID, out existingStop))
{
// update it - if cost smaller
if (newTotalCost < existingStop.TotalCost)
{
stopQueue.Remove(existingStop, existingStop.TotalCost);
existingStop.PreviousItem = stop;
existingStop.TotalCost = newTotalCost;
stopQueue.Enqueue(existingStop, existingStop.TotalCost);
}
}
else
{
if (newTotalCost < maxTime)
{
// add it - its new
var newStop = new TravelTimeAlgorithmItem
{
PreviousItem = stop,
Stop = reachableStop,
TotalCost = newTotalCost
};
stopQueue.Enqueue(newStop, newStop.TotalCost);
stopList[reachableStop.ID] = newStop;
}
}
}
}
PublicTransportResult result = new PublicTransportResult();
foreach (var stop in stopList.Values.OrderBy(x => x.TotalCost))
{
result.Items.Add(new TravelTimeCircle {
Center = stop.Stop.LatLng, TimeLeft = maxTime - stop.TotalCost
});
// check if this point is closest to stop
if (points != null)
{
points.ForEach(p =>
{
var time = 60 * p.Coords.DistanceInKmTo(stop.Stop.LatLng) / WalkingKmh + stop.TotalCost;
if (p.Time > time)
{
p.Time = time;
}
});
}
}
return(result);
}
