private static FuzzySet Merge(FuzzySet fs1, FuzzySet fs2, Func <double, double, double> MergeFt)
{
// New Fuzzy set
FuzzySet result = new FuzzySet(Math.Min(fs1.Min, fs2.Min), Math.Max(fs1.Max, fs2.Max));
// Creation of iterators on lists + initialization
List <Point2D> .Enumerator enum1 = fs1.Points.GetEnumerator();
List <Point2D> .Enumerator enum2 = fs2.Points.GetEnumerator();
enum1.MoveNext();
enum2.MoveNext();
Point2D oldPt1 = enum1.Current;
// Relative positions of fuzzy sets (to know when they intersect)
int relativePosition = 0;
int newRelativePosition = Math.Sign(enum1.Current.Y - enum2.Current.Y);
// Loop while there are points in the two collections
Boolean endOfList1 = false;
Boolean endOfList2 = false;
while (!endOfList1 && !endOfList2)
{
// New x values
double x1 = enum1.Current.X;
double x2 = enum2.Current.X;
// New current position
relativePosition = newRelativePosition;
newRelativePosition = Math.Sign(enum1.Current.Y - enum2.Current.Y);
if (relativePosition != newRelativePosition && relativePosition != 0 && newRelativePosition != 0)
{
// Positions have changed, so we have to compute the intersection and add it
// Compute the points coordinates
double x = (x1 == x2 ? oldPt1.X : Math.Min(x1, x2));
double xPrime = Math.Max(x1, x2);
// Intersection
double slope1 = (fs1.DegreeAtValue(xPrime) - fs1.DegreeAtValue(x)) / (xPrime - x);
double slope2 = (fs2.DegreeAtValue(xPrime) - fs2.DegreeAtValue(x)) / (xPrime - x);
double delta = (fs2.DegreeAtValue(x) - fs1.DegreeAtValue(x)) / (slope1 - slope2);
// Add point
result.Add(x + delta, fs1.DegreeAtValue(x + delta));
// Go on
if (x1 < x2)
{
oldPt1 = enum1.Current;
endOfList1 = !(enum1.MoveNext());
}
else if (x1 > x2)
{
endOfList2 = !(enum2.MoveNext());
}
}
else if (x1 == x2)
{
// The two points are on the same X, so we take the good value (eg min or max)
result.Add(x1, MergeFt(enum1.Current.Y, enum2.Current.Y));
oldPt1 = enum1.Current;
endOfList1 = !(enum1.MoveNext());
endOfList2 = !(enum2.MoveNext());
}
else if (x1 < x2)
{
// Fs1 point is first, we add the value (eg min or max) between the enum1 point and the degree for fs2
result.Add(x1, MergeFt(enum1.Current.Y, fs2.DegreeAtValue(x1)));
oldPt1 = enum1.Current;
endOfList1 = !(enum1.MoveNext());
}
else
{
// This time, it's fs2 first
result.Add(x2, MergeFt(fs1.DegreeAtValue(x2), enum2.Current.Y));
endOfList2 = !(enum2.MoveNext());
}
}
// Add end points
if (!endOfList1)
{
while (!endOfList1)
{
result.Add(enum1.Current.X, MergeFt(0, enum1.Current.Y));
endOfList1 = !enum1.MoveNext();
}
}
else if (!endOfList2)
{
while (!endOfList2)
{
result.Add(enum2.Current.X, MergeFt(0, enum2.Current.Y));
endOfList2 = !enum2.MoveNext();
}
}
return(result);
}