public static Tuple <double[], double, double, double> dixond(double[] items, int alpha)
{
int n = items.Length;
if (!(n >= 3 || n <= 30))
{
throw new Exception("Dixon function: it is required that count of samples be within [3, 30].");
}
if (!(alpha == 1 || alpha == 5))
{
throw new Exception("Dixon function: it is required that alpha be 1 or 5.");
}
double dixon = Dixon.GetValue(alpha, n);
double[] x = items.OrderBy(i => i).ToArray();
double r1;
double rn;
if (n <= 7)
{
r1 = (x[1] - x[0]) / (x[x.Length - 1] - x[0]);
rn = (x[x.Length - 1] - x[x.Length - 2]) / (x[x.Length - 1] - x[0]);
}
else if (n <= 10)
{
r1 = (x[1] - x[0]) / (x[x.Length - 2] - x[0]);
rn = (x[x.Length - 1] - x[x.Length - 2]) / (x[x.Length - 1] - x[1]);
}
else if (n <= 13)
{
r1 = (x[2] - x[0]) / (x[x.Length - 2] - x[0]);
rn = (x[x.Length - 1] - x[x.Length - 3]) / (x[x.Length - 1] - x[1]);
}
else
{
r1 = (x[2] - x[0]) / (x[x.Length - 3] - x[0]);
rn = (x[x.Length - 1] - x[x.Length - 3]) / (x[x.Length - 1] - x[2]);
}
bool removeFirst = r1 > rn && r1 > dixon;
bool removeLast = rn > r1 && rn > dixon;
List <double> removedItems = new List <double>();
if (removeFirst)
{
removedItems.Add(x.First());
}
if (removeLast)
{
removedItems.Add(x.Last());
}
return(new Tuple <double[], double, double, double>(removedItems.ToArray(), r1, rn, dixon));
}
public static double tdixon(int n, int alpha)
{
return(Dixon.GetValue(alpha, n));
}
