/// <summary>
/// Missing mapping to P objects
/// KdTree could be refactored to use P object instead of Math.Net
///
/// O(k * log n)
/// </summary>
/// <param name="s"></param>
/// <param name="origin"></param>
/// <param name="k"></param>
/// <param name="conf"></param>
/// <returns></returns>
public long UpdateKnn(IAlgorithm s, IP origin, KnnConfiguration conf)
{
if (conf == null) conf = new KnnConfiguration();
if (conf.SameTypeOnly) throw new NotImplementedException();
if (conf.MaxDistance.HasValue) throw new NotImplementedException();
var sw = new Stopwatch();
sw.Start();
var vector = new DenseVector(new[] { origin.X, origin.Y });
var nn = Tree.FindNearestNNeighbors(vector, conf.K).ToList();
s.Knn.Clear();
s.Knn.Origin = origin;
s.Knn.K = conf.K;
foreach (var i in nn)
{
var p = new P { X = i[0], Y = i[1] };
var dist = origin.Distance(p.X,p.Y);
s.Knn.NNs.Add(new PDist {Point = p, Distance = dist});
}
sw.Stop();
return sw.ElapsedMilliseconds;
}
/// <summary>
/// O(n * k * logk) // much faster than O(n logn) for k << n
/// </summary>
/// <param name="s"></param>
/// <param name="p"></param>
/// <param name="conf"></param>
/// <returns></returns>
public long UpdateKnn(IAlgorithm s, IP p, KnnConfiguration conf)
{
conf = conf ?? new KnnConfiguration();
var sw = new Stopwatch();
sw.Start();
s.Knn.Clear();
s.Knn.Origin = p;
s.Knn.K = conf.K;
//var all = new List<IPDist>(); // naive version
var sortedList2 = new SortedList2(); // better naive version
var n = s.Points.Count;
for (var i = 0; i < n; i++)
{
var p1 = s.Points[i];
if (p.Equals(p1))
{
continue; // don't include origin
}
if (conf.SameTypeOnly && p.Type != p1.Type)
{
continue; // only same type used
}
var dist = p.Distance(p1.X, p1.Y);
if (dist >= conf.MaxDistance)
{
continue;
}
var pdist = new PDist {
Point = p1, Distance = dist
};
//all.Add(pdist); // naive version
sortedList2.Add(pdist, conf.K); // better naive version
}
//s.Knn.NNs = all.OrderBy(i => i.Distance).Take(conf.K).ToList(); // O(n logn)
s.Knn.NNs = sortedList2.GetAll(); // O(n * k * logk) // better naive version
sw.Stop();
return(sw.ElapsedMilliseconds);
}
/// <summary>
/// Missing mapping to P objects
/// KdTree could be refactored to use P object instead of Math.Net
///
/// O(k * log n)
/// </summary>
/// <param name="s"></param>
/// <param name="origin"></param>
/// <param name="k"></param>
/// <param name="conf"></param>
/// <returns></returns>
public long UpdateKnn(IAlgorithm s, IP origin, KnnConfiguration conf)
{
if (conf == null)
{
conf = new KnnConfiguration();
}
if (conf.SameTypeOnly)
{
throw new NotImplementedException();
}
if (conf.MaxDistance.HasValue)
{
throw new NotImplementedException();
}
var sw = new Stopwatch();
sw.Start();
var vector = new DenseVector(new[] { origin.X, origin.Y });
var nn = Tree.FindNearestNNeighbors(vector, conf.K).ToList();
s.Knn.Clear();
s.Knn.Origin = origin;
s.Knn.K = conf.K;
foreach (var i in nn)
{
var p = new P {
X = i[0], Y = i[1]
};
var dist = origin.Distance(p.X, p.Y);
s.Knn.NNs.Add(new PDist {
Point = p, Distance = dist
});
}
sw.Stop();
return(sw.ElapsedMilliseconds);
}
/// <summary>
/// O(n * k * logk) // much faster than O(n logn) for k << n
/// </summary>
/// <param name="s"></param>
/// <param name="p"></param>
/// <param name="conf"></param>
/// <returns></returns>
public override long UpdateKnn(IAlgorithm s, IP p, KnnConfiguration conf)
{
if (conf == null) conf = new KnnConfiguration();
var sw = new Stopwatch();
sw.Start();
s.Knn.Clear();
s.Knn.Origin = p;
s.Knn.K = conf.K;
//var all = new List<IPDist>();
var sortedList2 = new SortedList2();
var n = s.Points.Count;
for (var i = 0; i < n; i++)
{
var p1 = s.Points[i];
if (p.Equals(p1)) continue; // don't include origin
if (conf.SameTypeOnly && p.Type != p1.Type) continue; // only same type used
var dist = p.Distance(p1.X, p1.Y);
if (dist >= conf.MaxDistance) continue;
var pdist = new PDist { Point = p1, Distance = dist };
//all.Add(pdist);
sortedList2.Add(pdist, conf.K);
}
//s.Knn.NNs = all.OrderBy(i => i.Distance).Take(conf.K).ToList(); // O(n logn)
s.Knn.NNs = sortedList2.GetAll(); // O(n * k * logk)
sw.Stop();
return sw.ElapsedMilliseconds;
}