public void CompareSpeedOfSorting_SmallBalancedSort_vs_HilbertIndex()
{
var points = TestData(20000, 50, 20, 1000000, 100, 500, out int bitsPerDimension);
var timer1 = new Stopwatch();
var timer2 = new Stopwatch();
var timer3 = new Stopwatch();
// 1. HilbertIndex
timer1.Start();
var hIndex = new HilbertIndex(points.Select(p => new HilbertPoint(p.Coordinates, bitsPerDimension)));
var sortedPointsFromIndex = hIndex.SortedPoints;
timer1.Stop();
var hilbertIndexTime = timer1.ElapsedMilliseconds;
// 2. HilbertSort.SmallBalancedSort
timer2.Start();
timer3.Start();
PointBalancer balancer = new PointBalancer(points);
timer3.Stop();
HilbertSort.SmallBalancedSort(points, ref balancer);
timer2.Stop();
var inplaceSortTime = timer2.ElapsedMilliseconds;
var balancerTime = timer3.ElapsedMilliseconds;
var message = $"HilbertIndex required {hilbertIndexTime/1000.0} sec. In-place Sort required {inplaceSortTime/1000.0} sec, of which {balancerTime/1000.0} sec is Balancer ctor. Relative Cost = {HilbertSort.RelativeSortCost}";
Console.WriteLine(message);
Assert.Greater(hilbertIndexTime, inplaceSortTime, message);
}
public void InPlaceSort_NarrowClusters()
{
var points = TestData(20000, 50, 20, 1000000, 10, 30, out int bitsPerDimension);
PointBalancer balancer = new PointBalancer(points);
var unoptimizedSort = HilbertSort.BalancedSort(points.ToList(), ref balancer).ToArray();
HilbertSort.SmallBalancedSort(points, ref balancer);
CollectionAssert.AreEqual(unoptimizedSort, points, "Not in same order");
}
public void InPlaceSortRelativeCost()
{
var clusters = new[] { 10, 20, 50, 100 };
var stdDeviations = new[] { 20, 100, 200, 1000, 2000 };
var dimensions = 50;
var numPoints = 20000;
var report = "Clusters,Standard Deviation,Relative Cost\n";
foreach (var k in clusters)
{
foreach (var sd in stdDeviations)
{
var points = TestData(numPoints, dimensions, k, 1000000, sd, sd, out int bitsPerDimension);
PointBalancer balancer = new PointBalancer(points);
HilbertSort.SmallBalancedSort(points, ref balancer);
var cost = HilbertSort.RelativeSortCost;
report += $"{k},{sd},{cost}\n";
}
}
Console.WriteLine($"\n\nFinal report:\n\n{report}");
}