////////////////////////////////////////////////////NEED ADJUSTMENT IN DISTANCE MEASURE
/// <summary>
/// Recursively searches the tree for the nearest entry. Other queries
/// call execute() on an IntProcedure when a matching entry is found;
/// however nearest() must store the entry Ids as it searches the tree,
/// in case a nearer entry is found.
/// Uses the member variable nearestIds to store the nearest
/// entry IDs.
/// </summary>
/// <remarks>TODO rewrite this to be non-recursive?</remarks>
private double nearest(SubSequence p, Node <T> n, double nearestDistance)
{
for (int i = 0; i < n.entryCount; i++)
{
double tempDistance = n.entries[i].distance(p);
if (n.isLeaf())
{ // for leaves, the distance is an actual nearest distance
if (tempDistance < nearestDistance)
{
nearestDistance = tempDistance;
nearestIds.Clear();
}
if (tempDistance <= nearestDistance)
{
nearestIds.Add(n.ids[i]);
}
}
else
{ // for index nodes, only go into them if they potentially could have
// a rectangle nearer than actualNearest
if (tempDistance <= nearestDistance)
{
// search the child node
nearestDistance = nearest(p, getNode(n.ids[i]), nearestDistance);
}
}
}
return(nearestDistance);
}
/// <summary>
/// Retrieve nearest items to a point in radius furthestDistance
/// </summary>
public List <T> Nearest(SubSequence p, double furthestDistance)
{
List <T> retval = new List <T>();
nearest(p, delegate(int id)
{
retval.Add(IdsToItems[id]);
}, furthestDistance);
return(retval);
}
private void nearest(SubSequence p, intproc v, double furthestDistance)
{
Node <T> rootNode = getNode(rootNodeId);
nearest(p, rootNode, furthestDistance);
foreach (int id in nearestIds)
{
v(id);
}
nearestIds.Clear();
}
/**
* Return the distance between this rectangle and the passed point.
* If the rectangle contains the point, the distance is zero.
*
* @param p Point to find the distance to
*
* @return distance beween this rectangle and the passed point.
*/
internal double distance(SubSequence p)
{
double distanceSquared = 0;
for (int i = 0; i < DIMENSIONS; i++)
{
double greatestMin = Math.Max(min[i], p.coordinates[i]);
double leastMax = Math.Min(max[i], p.coordinates[i]);
if (greatestMin > leastMax)
{
distanceSquared += ((greatestMin - leastMax) * (greatestMin - leastMax));
}
}
return((double)Math.Sqrt(distanceSquared));
}
