| public SubtractFast ( int x, int y, double target ) : void | ||
| x | int | |
| y | int | |
| target | double | |
| return | void | |
/// <summary>
/// Finds (dimension + 1) initial points.
/// </summary>
/// <param name="extremes"></param>
/// <returns></returns>
private List <VertexWrap> FindInitialPoints(List <VertexWrap> extremes)
{
List <VertexWrap> initialPoints = new List <VertexWrap>();// { extremes[0], extremes[1] };
VertexWrap first = null, second = null;
double maxDist = 0;
double[] temp = new double[Dimension];
for (int i = 0; i < extremes.Count - 1; i++)
{
var a = extremes[i];
for (int j = i + 1; j < extremes.Count; j++)
{
var b = extremes[j];
MathHelper.SubtractFast(a.PositionData, b.PositionData, temp);
var dist = MathHelper.LengthSquared(temp);
if (dist > maxDist)
{
first = a;
second = b;
maxDist = dist;
}
}
}
initialPoints.Add(first);
initialPoints.Add(second);
for (int i = 2; i <= Dimension; i++)
{
double maximum = 0.000001;
VertexWrap maxPoint = null;
for (int j = 0; j < extremes.Count; j++)
{
var extreme = extremes[j];
if (initialPoints.Contains(extreme))
{
continue;
}
var val = GetSquaredDistanceSum(extreme, initialPoints);
if (val > maximum)
{
maximum = val;
maxPoint = extreme;
}
}
if (maxPoint != null)
{
initialPoints.Add(maxPoint);
}
else
{
int vCount = InputVertices.Count;
for (int j = 0; j < vCount; j++)
{
var point = InputVertices[j];
if (initialPoints.Contains(point))
{
continue;
}
var val = GetSquaredDistanceSum(point, initialPoints);
if (val > maximum)
{
maximum = val;
maxPoint = point;
}
}
if (maxPoint != null)
{
initialPoints.Add(maxPoint);
}
else
{
ThrowSingular();
}
}
}
return(initialPoints);
}
/// <summary>
/// Finds (dimension + 1) initial points.
/// </summary>
/// <param name="extremes"></param>
/// <returns></returns>
private List <int> FindInitialPoints(List <int> extremes)
{
List <int> initialPoints = new List <int>();
int first = -1, second = -1;
double maxDist = 0;
double[] temp = new double[Dimension];
for (int i = 0; i < extremes.Count - 1; i++)
{
var a = extremes[i];
for (int j = i + 1; j < extremes.Count; j++)
{
var b = extremes[j];
MathHelper.SubtractFast(a, b, temp);
var dist = MathHelper.LengthSquared(temp);
if (dist > maxDist)
{
first = a;
second = b;
maxDist = dist;
}
}
}
initialPoints.Add(first);
initialPoints.Add(second);
for (int i = 2; i <= Dimension; i++)
{
double maximum = double.NegativeInfinity;
int maxPoint = -1;
for (int j = 0; j < extremes.Count; j++)
{
var extreme = extremes[j];
if (initialPoints.Contains(extreme))
{
continue;
}
var val = GetSquaredDistanceSum(extreme, initialPoints);
if (val > maximum)
{
maximum = val;
maxPoint = extreme;
}
}
if (maxPoint >= 0)
{
initialPoints.Add(maxPoint);
}
else
{
int vCount = Vertices.Length;
for (int j = 0; j < vCount; j++)
{
if (initialPoints.Contains(j))
{
continue;
}
var val = GetSquaredDistanceSum(j, initialPoints);
if (val > maximum)
{
maximum = val;
maxPoint = j;
}
}
if (maxPoint >= 0)
{
initialPoints.Add(maxPoint);
}
else
{
ThrowSingular();
}
}
}
return(initialPoints);
}
