private MembershipFunction combine(MembershipFunction first, MembershipFunction second)
{
if (!first.Any())
return second;
if (!second.Any())
return first;
var scanPoints = new List<double>();
scanPoints.AddRange(first.Keys);
foreach (var key in second.Keys.Where(key => !scanPoints.Contains(key)))
scanPoints.Add(key);
scanPoints.Sort();
var result = new MembershipFunction();
foreach (var scanPoint in scanPoints)
{
var valueFirst = first.Apply(scanPoint);
var valueSecond = second.Apply(scanPoint);
result.Add(scanPoint, valueFirst + valueSecond);
}
return result.ClearUp();
}
private static MembershipFunction combine(MembershipFunction first, MembershipFunction second)
{
if (!first.Any())
return second;
if (!second.Any())
return first;
var scanPoints = getScanPoints(first, second);
var result = new MembershipFunction();
for (var i = 0; i < scanPoints.Count; i++)
{
var scanPoint = scanPoints[i];
var valueFirst = first.Apply(scanPoint);
var valueSecond = second.Apply(scanPoint);
result.Add(scanPoint, Math.Max(valueFirst, valueSecond));
// Check if there is an intersection between this scan point and the next
// and add it to the list of scan points:
var nextKeyFirst = getNextKey(first, scanPoint);
var nextKeySecond = getNextKey(second, scanPoint);
if (nextKeyFirst.HasValue && nextKeySecond.HasValue)
{
var nextValueFirst = first[nextKeyFirst.Value];
var nextValueSecond = second[nextKeySecond.Value];
if (valueFirst >= valueSecond && nextValueFirst < nextValueSecond ||
valueFirst < valueSecond && nextValueFirst >= nextValueSecond)
{
var lineFirst = new LineSegment(new Point(scanPoint, valueFirst),
new Point(nextKeyFirst.Value, nextValueFirst));
var lineSecond = new LineSegment(new Point(scanPoint, valueSecond),
new Point(nextKeySecond.Value, nextValueSecond));
var intersection = lineFirst.Intersect(lineSecond);
if (intersection != null && !scanPoints.Contains(intersection.X) && intersection.X > scanPoint)
scanPoints.Insert(i + 1, intersection.X);
}
}
}
return result.ClearUp();
}
